Hyper-V is adding some low speed "specialty" synthetic devices.
This patch series propose the solution to support these devices.
Instead of writing new kernel-level VMBus drivers for all of
these devices, we propose a solution wherein these devices are
made accessible to user space through a dedicated UIO-based
hv_vmbus_client driver, allowing for efficient device handling
via user space drivers. This solution aims to optimize the
development process by eliminating the need to create
individual kernel-level VMBus drivers for each device and
provide flexibility to user space applications to control the
ring buffer independently.
Since all these new synthetic devices are low speed devices,
they don't support monitor bits and we must use vmbus_setevent()
to enable interrupts from the host. The new uio driver supports
all these requirements effectively. Additionally, this new driver
also provide the support for having smaller/cutom ringbuffer
size.
Furthermore, this patch series includes a revision of the fcopy
application to leverage the new interface seamlessly along with
removal of old driver and application. However, please note that
the development of other similar drivers is still a work in
progress, and will be shared as they become available.
Saurabh Sengar (5):
uio: Add hv_vmbus_client driver
tools: hv: Add vmbus_bufring
tools: hv: Add new fcopy application based on uio driver
tools: hv: Remove hv_fcopy_daemon
Drivers: hv: Remove fcopy driver
drivers/hv/Makefile | 2 +-
drivers/hv/hv_fcopy.c | 427 --------------------------
drivers/hv/hv_util.c | 12 -
drivers/uio/Kconfig | 12 +
drivers/uio/Makefile | 1 +
drivers/uio/uio_hv_vmbus_client.c | 232 ++++++++++++++
tools/hv/Build | 3 +-
tools/hv/Makefile | 10 +-
tools/hv/hv_fcopy_daemon.c | 266 ----------------
tools/hv/hv_fcopy_uio_daemon.c | 491 ++++++++++++++++++++++++++++++
tools/hv/vmbus_bufring.c | 324 ++++++++++++++++++++
tools/hv/vmbus_bufring.h | 158 ++++++++++
12 files changed, 1226 insertions(+), 712 deletions(-)
delete mode 100644 drivers/hv/hv_fcopy.c
create mode 100644 drivers/uio/uio_hv_vmbus_client.c
delete mode 100644 tools/hv/hv_fcopy_daemon.c
create mode 100644 tools/hv/hv_fcopy_uio_daemon.c
create mode 100644 tools/hv/vmbus_bufring.c
create mode 100644 tools/hv/vmbus_bufring.h
--
2.34.1
As the new fcopy application using uio is introduced, remove
obsolete hv_fcopy_daemon.c
Signed-off-by: Saurabh Sengar <[email protected]>
---
tools/hv/hv_fcopy_daemon.c | 266 -------------------------------------
1 file changed, 266 deletions(-)
delete mode 100644 tools/hv/hv_fcopy_daemon.c
diff --git a/tools/hv/hv_fcopy_daemon.c b/tools/hv/hv_fcopy_daemon.c
deleted file mode 100644
index 16d629b22c25..000000000000
--- a/tools/hv/hv_fcopy_daemon.c
+++ /dev/null
@@ -1,266 +0,0 @@
-// SPDX-License-Identifier: GPL-2.0-only
-/*
- * An implementation of host to guest copy functionality for Linux.
- *
- * Copyright (C) 2014, Microsoft, Inc.
- *
- * Author : K. Y. Srinivasan <[email protected]>
- */
-
-
-#include <sys/types.h>
-#include <stdio.h>
-#include <stdlib.h>
-#include <unistd.h>
-#include <string.h>
-#include <errno.h>
-#include <linux/hyperv.h>
-#include <linux/limits.h>
-#include <syslog.h>
-#include <sys/stat.h>
-#include <fcntl.h>
-#include <getopt.h>
-
-static int target_fd;
-static char target_fname[PATH_MAX];
-static unsigned long long filesize;
-
-static int hv_start_fcopy(struct hv_start_fcopy *smsg)
-{
- int error = HV_E_FAIL;
- char *q, *p;
-
- filesize = 0;
- p = (char *)smsg->path_name;
- snprintf(target_fname, sizeof(target_fname), "%s/%s",
- (char *)smsg->path_name, (char *)smsg->file_name);
-
- syslog(LOG_INFO, "Target file name: %s", target_fname);
- /*
- * Check to see if the path is already in place; if not,
- * create if required.
- */
- while ((q = strchr(p, '/')) != NULL) {
- if (q == p) {
- p++;
- continue;
- }
- *q = '\0';
- if (access((char *)smsg->path_name, F_OK)) {
- if (smsg->copy_flags & CREATE_PATH) {
- if (mkdir((char *)smsg->path_name, 0755)) {
- syslog(LOG_ERR, "Failed to create %s",
- (char *)smsg->path_name);
- goto done;
- }
- } else {
- syslog(LOG_ERR, "Invalid path: %s",
- (char *)smsg->path_name);
- goto done;
- }
- }
- p = q + 1;
- *q = '/';
- }
-
- if (!access(target_fname, F_OK)) {
- syslog(LOG_INFO, "File: %s exists", target_fname);
- if (!(smsg->copy_flags & OVER_WRITE)) {
- error = HV_ERROR_ALREADY_EXISTS;
- goto done;
- }
- }
-
- target_fd = open(target_fname,
- O_RDWR | O_CREAT | O_TRUNC | O_CLOEXEC, 0744);
- if (target_fd == -1) {
- syslog(LOG_INFO, "Open Failed: %s", strerror(errno));
- goto done;
- }
-
- error = 0;
-done:
- if (error)
- target_fname[0] = '\0';
- return error;
-}
-
-static int hv_copy_data(struct hv_do_fcopy *cpmsg)
-{
- ssize_t bytes_written;
- int ret = 0;
-
- bytes_written = pwrite(target_fd, cpmsg->data, cpmsg->size,
- cpmsg->offset);
-
- filesize += cpmsg->size;
- if (bytes_written != cpmsg->size) {
- switch (errno) {
- case ENOSPC:
- ret = HV_ERROR_DISK_FULL;
- break;
- default:
- ret = HV_E_FAIL;
- break;
- }
- syslog(LOG_ERR, "pwrite failed to write %llu bytes: %ld (%s)",
- filesize, (long)bytes_written, strerror(errno));
- }
-
- return ret;
-}
-
-/*
- * Reset target_fname to "" in the two below functions for hibernation: if
- * the fcopy operation is aborted by hibernation, the daemon should remove the
- * partially-copied file; to achieve this, the hv_utils driver always fakes a
- * CANCEL_FCOPY message upon suspend, and later when the VM resumes back,
- * the daemon calls hv_copy_cancel() to remove the file; if a file is copied
- * successfully before suspend, hv_copy_finished() must reset target_fname to
- * avoid that the file can be incorrectly removed upon resume, since the faked
- * CANCEL_FCOPY message is spurious in this case.
- */
-static int hv_copy_finished(void)
-{
- close(target_fd);
- target_fname[0] = '\0';
- return 0;
-}
-static int hv_copy_cancel(void)
-{
- close(target_fd);
- if (strlen(target_fname) > 0) {
- unlink(target_fname);
- target_fname[0] = '\0';
- }
- return 0;
-
-}
-
-void print_usage(char *argv[])
-{
- fprintf(stderr, "Usage: %s [options]\n"
- "Options are:\n"
- " -n, --no-daemon stay in foreground, don't daemonize\n"
- " -h, --help print this help\n", argv[0]);
-}
-
-int main(int argc, char *argv[])
-{
- int fcopy_fd = -1;
- int error;
- int daemonize = 1, long_index = 0, opt;
- int version = FCOPY_CURRENT_VERSION;
- union {
- struct hv_fcopy_hdr hdr;
- struct hv_start_fcopy start;
- struct hv_do_fcopy copy;
- __u32 kernel_modver;
- } buffer = { };
- int in_handshake;
-
- static struct option long_options[] = {
- {"help", no_argument, 0, 'h' },
- {"no-daemon", no_argument, 0, 'n' },
- {0, 0, 0, 0 }
- };
-
- while ((opt = getopt_long(argc, argv, "hn", long_options,
- &long_index)) != -1) {
- switch (opt) {
- case 'n':
- daemonize = 0;
- break;
- case 'h':
- default:
- print_usage(argv);
- exit(EXIT_FAILURE);
- }
- }
-
- if (daemonize && daemon(1, 0)) {
- syslog(LOG_ERR, "daemon() failed; error: %s", strerror(errno));
- exit(EXIT_FAILURE);
- }
-
- openlog("HV_FCOPY", 0, LOG_USER);
- syslog(LOG_INFO, "starting; pid is:%d", getpid());
-
-reopen_fcopy_fd:
- if (fcopy_fd != -1)
- close(fcopy_fd);
- /* Remove any possible partially-copied file on error */
- hv_copy_cancel();
- in_handshake = 1;
- fcopy_fd = open("/dev/vmbus/hv_fcopy", O_RDWR);
-
- if (fcopy_fd < 0) {
- syslog(LOG_ERR, "open /dev/vmbus/hv_fcopy failed; error: %d %s",
- errno, strerror(errno));
- exit(EXIT_FAILURE);
- }
-
- /*
- * Register with the kernel.
- */
- if ((write(fcopy_fd, &version, sizeof(int))) != sizeof(int)) {
- syslog(LOG_ERR, "Registration failed: %s", strerror(errno));
- exit(EXIT_FAILURE);
- }
-
- while (1) {
- /*
- * In this loop we process fcopy messages after the
- * handshake is complete.
- */
- ssize_t len;
-
- len = pread(fcopy_fd, &buffer, sizeof(buffer), 0);
- if (len < 0) {
- syslog(LOG_ERR, "pread failed: %s", strerror(errno));
- goto reopen_fcopy_fd;
- }
-
- if (in_handshake) {
- if (len != sizeof(buffer.kernel_modver)) {
- syslog(LOG_ERR, "invalid version negotiation");
- exit(EXIT_FAILURE);
- }
- in_handshake = 0;
- syslog(LOG_INFO, "kernel module version: %u",
- buffer.kernel_modver);
- continue;
- }
-
- switch (buffer.hdr.operation) {
- case START_FILE_COPY:
- error = hv_start_fcopy(&buffer.start);
- break;
- case WRITE_TO_FILE:
- error = hv_copy_data(&buffer.copy);
- break;
- case COMPLETE_FCOPY:
- error = hv_copy_finished();
- break;
- case CANCEL_FCOPY:
- error = hv_copy_cancel();
- break;
-
- default:
- error = HV_E_FAIL;
- syslog(LOG_ERR, "Unknown operation: %d",
- buffer.hdr.operation);
-
- }
-
- /*
- * pwrite() may return an error due to the faked CANCEL_FCOPY
- * message upon hibernation. Ignore the error by resetting the
- * dev file, i.e. closing and re-opening it.
- */
- if (pwrite(fcopy_fd, &error, sizeof(int), 0) != sizeof(int)) {
- syslog(LOG_ERR, "pwrite failed: %s", strerror(errno));
- goto reopen_fcopy_fd;
- }
- }
-}
--
2.34.1
New fcopy application which utilizes uio_hv_vmbus_client driver
Signed-off-by: Saurabh Sengar <[email protected]>
---
tools/hv/Build | 3 +-
tools/hv/Makefile | 10 +-
tools/hv/hv_fcopy_uio_daemon.c | 491 +++++++++++++++++++++++++++++++++
3 files changed, 498 insertions(+), 6 deletions(-)
create mode 100644 tools/hv/hv_fcopy_uio_daemon.c
diff --git a/tools/hv/Build b/tools/hv/Build
index 6cf51fa4b306..7d1f1698069b 100644
--- a/tools/hv/Build
+++ b/tools/hv/Build
@@ -1,3 +1,4 @@
hv_kvp_daemon-y += hv_kvp_daemon.o
hv_vss_daemon-y += hv_vss_daemon.o
-hv_fcopy_daemon-y += hv_fcopy_daemon.o
+hv_fcopy_uio_daemon-y += hv_fcopy_uio_daemon.o
+hv_fcopy_uio_daemon-y += vmbus_bufring.o
diff --git a/tools/hv/Makefile b/tools/hv/Makefile
index fe770e679ae8..944180cf916e 100644
--- a/tools/hv/Makefile
+++ b/tools/hv/Makefile
@@ -17,7 +17,7 @@ MAKEFLAGS += -r
override CFLAGS += -O2 -Wall -g -D_GNU_SOURCE -I$(OUTPUT)include
-ALL_TARGETS := hv_kvp_daemon hv_vss_daemon hv_fcopy_daemon
+ALL_TARGETS := hv_kvp_daemon hv_vss_daemon hv_fcopy_uio_daemon
ALL_PROGRAMS := $(patsubst %,$(OUTPUT)%,$(ALL_TARGETS))
ALL_SCRIPTS := hv_get_dhcp_info.sh hv_get_dns_info.sh hv_set_ifconfig.sh
@@ -39,10 +39,10 @@ $(HV_VSS_DAEMON_IN): FORCE
$(OUTPUT)hv_vss_daemon: $(HV_VSS_DAEMON_IN)
$(QUIET_LINK)$(CC) $(CFLAGS) $(LDFLAGS) $< -o $@
-HV_FCOPY_DAEMON_IN := $(OUTPUT)hv_fcopy_daemon-in.o
-$(HV_FCOPY_DAEMON_IN): FORCE
- $(Q)$(MAKE) $(build)=hv_fcopy_daemon
-$(OUTPUT)hv_fcopy_daemon: $(HV_FCOPY_DAEMON_IN)
+HV_FCOPY_UIO_DAEMON_IN := $(OUTPUT)hv_fcopy_uio_daemon-in.o
+$(HV_FCOPY_UIO_DAEMON_IN): FORCE
+ $(Q)$(MAKE) $(build)=hv_fcopy_uio_daemon
+$(OUTPUT)hv_fcopy_uio_daemon: $(HV_FCOPY_UIO_DAEMON_IN)
$(QUIET_LINK)$(CC) $(CFLAGS) $(LDFLAGS) $< -o $@
clean:
diff --git a/tools/hv/hv_fcopy_uio_daemon.c b/tools/hv/hv_fcopy_uio_daemon.c
new file mode 100644
index 000000000000..d20e8040b754
--- /dev/null
+++ b/tools/hv/hv_fcopy_uio_daemon.c
@@ -0,0 +1,491 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * An implementation of host to guest copy functionality for Linux.
+ *
+ * Copyright (C) 2023, Microsoft, Inc.
+ *
+ * Author : K. Y. Srinivasan <[email protected]>
+ * Author : Saurabh Sengar <[email protected]>
+ *
+ */
+
+#include <dirent.h>
+#include <errno.h>
+#include <fcntl.h>
+#include <getopt.h>
+#include <locale.h>
+#include <stdbool.h>
+#include <stddef.h>
+#include <stdint.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <syslog.h>
+#include <unistd.h>
+#include <wchar.h>
+#include <sys/stat.h>
+#include <linux/hyperv.h>
+#include <linux/limits.h>
+#include "vmbus_bufring.h"
+
+#define ICMSGTYPE_NEGOTIATE 0
+#define ICMSGTYPE_FCOPY 7
+
+#define WIN8_SRV_MAJOR 1
+#define WIN8_SRV_MINOR 1
+#define WIN8_SRV_VERSION (WIN8_SRV_MAJOR << 16 | WIN8_SRV_MINOR)
+
+#define MAX_FOLDER_NAME 15
+#define MAX_PATH_LEN 15
+#define FCOPY_SYSFS_CHAN "/sys/bus/vmbus/devices/eb765408-105f-49b6-b4aa-c123b64d17d4/channels"
+#define FCOPY_UIO "/sys/bus/vmbus/devices/eb765408-105f-49b6-b4aa-c123b64d17d4/uio"
+
+#define FCOPY_VER_COUNT 1
+static const int fcopy_versions[] = {
+ WIN8_SRV_VERSION
+};
+
+#define FW_VER_COUNT 1
+static const int fw_versions[] = {
+ UTIL_FW_VERSION
+};
+
+#define HV_RING_SIZE (4 * 4096)
+
+unsigned char desc[HV_RING_SIZE];
+
+static int target_fd;
+static char target_fname[PATH_MAX];
+static unsigned long long filesize;
+
+static int hv_fcopy_create_file(char *file_name, char *path_name, __u32 flags)
+{
+ int error = HV_E_FAIL;
+ char *q, *p;
+
+ filesize = 0;
+ p = (char *)path_name;
+ snprintf(target_fname, sizeof(target_fname), "%s/%s",
+ (char *)path_name, (char *)file_name);
+
+ /*
+ * Check to see if the path is already in place; if not,
+ * create if required.
+ */
+ while ((q = strchr(p, '/')) != NULL) {
+ if (q == p) {
+ p++;
+ continue;
+ }
+ *q = '\0';
+ if (access(path_name, F_OK)) {
+ if (flags & CREATE_PATH) {
+ if (mkdir(path_name, 0755)) {
+ syslog(LOG_ERR, "Failed to create %s",
+ path_name);
+ goto done;
+ }
+ } else {
+ syslog(LOG_ERR, "Invalid path: %s", path_name);
+ goto done;
+ }
+ }
+ p = q + 1;
+ *q = '/';
+ }
+
+ if (!access(target_fname, F_OK)) {
+ syslog(LOG_INFO, "File: %s exists", target_fname);
+ if (!(flags & OVER_WRITE)) {
+ error = HV_ERROR_ALREADY_EXISTS;
+ goto done;
+ }
+ }
+
+ target_fd = open(target_fname,
+ O_RDWR | O_CREAT | O_TRUNC | O_CLOEXEC, 0744);
+ if (target_fd == -1) {
+ syslog(LOG_INFO, "Open Failed: %s", strerror(errno));
+ goto done;
+ }
+
+ error = 0;
+done:
+ if (error)
+ target_fname[0] = '\0';
+ return error;
+}
+
+/* copy the data into the file */
+static int hv_copy_data(struct hv_do_fcopy *cpmsg)
+{
+ ssize_t len;
+ int ret = 0;
+
+ len = pwrite(target_fd, cpmsg->data, cpmsg->size, cpmsg->offset);
+
+ filesize += cpmsg->size;
+ if (len != cpmsg->size) {
+ switch (errno) {
+ case ENOSPC:
+ ret = HV_ERROR_DISK_FULL;
+ break;
+ default:
+ ret = HV_E_FAIL;
+ break;
+ }
+ syslog(LOG_ERR, "pwrite failed to write %llu bytes: %ld (%s)",
+ filesize, (long)len, strerror(errno));
+ }
+
+ return ret;
+}
+
+static int hv_copy_finished(void)
+{
+ close(target_fd);
+ target_fname[0] = '\0';
+
+ return 0;
+}
+
+static void print_usage(char *argv[])
+{
+ fprintf(stderr, "Usage: %s [options]\n"
+ "Options are:\n"
+ " -n, --no-daemon stay in foreground, don't daemonize\n"
+ " -h, --help print this help\n", argv[0]);
+}
+
+static bool vmbus_prep_negotiate_resp(struct icmsg_hdr *icmsghdrp, unsigned char *buf,
+ unsigned int buflen, const int *fw_version, int fw_vercnt,
+ const int *srv_version, int srv_vercnt,
+ int *nego_fw_version, int *nego_srv_version)
+{
+ int icframe_major, icframe_minor;
+ int icmsg_major, icmsg_minor;
+ int fw_major, fw_minor;
+ int srv_major, srv_minor;
+ int i, j;
+ bool found_match = false;
+ struct icmsg_negotiate *negop;
+
+ /* Check that there's enough space for icframe_vercnt, icmsg_vercnt */
+ if (buflen < ICMSG_HDR + offsetof(struct icmsg_negotiate, reserved)) {
+ syslog(LOG_ERR, "Invalid icmsg negotiate");
+ return false;
+ }
+
+ icmsghdrp->icmsgsize = 0x10;
+ negop = (struct icmsg_negotiate *)&buf[ICMSG_HDR];
+
+ icframe_major = negop->icframe_vercnt;
+ icframe_minor = 0;
+
+ icmsg_major = negop->icmsg_vercnt;
+ icmsg_minor = 0;
+
+ /* Validate negop packet */
+ if (icframe_major > IC_VERSION_NEGOTIATION_MAX_VER_COUNT ||
+ icmsg_major > IC_VERSION_NEGOTIATION_MAX_VER_COUNT ||
+ ICMSG_NEGOTIATE_PKT_SIZE(icframe_major, icmsg_major) > buflen) {
+ syslog(LOG_ERR, "Invalid icmsg negotiate - icframe_major: %u, icmsg_major: %u\n",
+ icframe_major, icmsg_major);
+ goto fw_error;
+ }
+
+ /*
+ * Select the framework version number we will
+ * support.
+ */
+
+ for (i = 0; i < fw_vercnt; i++) {
+ fw_major = (fw_version[i] >> 16);
+ fw_minor = (fw_version[i] & 0xFFFF);
+
+ for (j = 0; j < negop->icframe_vercnt; j++) {
+ if (negop->icversion_data[j].major == fw_major &&
+ negop->icversion_data[j].minor == fw_minor) {
+ icframe_major = negop->icversion_data[j].major;
+ icframe_minor = negop->icversion_data[j].minor;
+ found_match = true;
+ break;
+ }
+ }
+
+ if (found_match)
+ break;
+ }
+
+ if (!found_match)
+ goto fw_error;
+
+ found_match = false;
+
+ for (i = 0; i < srv_vercnt; i++) {
+ srv_major = (srv_version[i] >> 16);
+ srv_minor = (srv_version[i] & 0xFFFF);
+
+ for (j = negop->icframe_vercnt;
+ (j < negop->icframe_vercnt + negop->icmsg_vercnt);
+ j++) {
+ if (negop->icversion_data[j].major == srv_major &&
+ negop->icversion_data[j].minor == srv_minor) {
+ icmsg_major = negop->icversion_data[j].major;
+ icmsg_minor = negop->icversion_data[j].minor;
+ found_match = true;
+ break;
+ }
+ }
+
+ if (found_match)
+ break;
+ }
+
+ /*
+ * Respond with the framework and service
+ * version numbers we can support.
+ */
+fw_error:
+ if (!found_match) {
+ negop->icframe_vercnt = 0;
+ negop->icmsg_vercnt = 0;
+ } else {
+ negop->icframe_vercnt = 1;
+ negop->icmsg_vercnt = 1;
+ }
+
+ if (nego_fw_version)
+ *nego_fw_version = (icframe_major << 16) | icframe_minor;
+
+ if (nego_srv_version)
+ *nego_srv_version = (icmsg_major << 16) | icmsg_minor;
+
+ negop->icversion_data[0].major = icframe_major;
+ negop->icversion_data[0].minor = icframe_minor;
+ negop->icversion_data[1].major = icmsg_major;
+ negop->icversion_data[1].minor = icmsg_minor;
+
+ return found_match;
+}
+
+static void wcstoutf8(char *dest, const __u16 *src, size_t dest_size)
+{
+ size_t len = 0;
+
+ while (len < dest_size) {
+ if (src[len] < 0x80)
+ dest[len++] = (char)(*src++);
+ else
+ dest[len++] = 'X';
+ }
+
+ dest[len] = '\0';
+}
+
+static int hv_fcopy_start(struct hv_start_fcopy *smsg_in)
+{
+ setlocale(LC_ALL, "en_US.utf8");
+ size_t file_size, path_size;
+ char *file_name, *path_name;
+ char *in_file_name = (char *)smsg_in->file_name;
+ char *in_path_name = (char *)smsg_in->path_name;
+
+ file_size = wcstombs(NULL, (const wchar_t *restrict)in_file_name, 0) + 1;
+ path_size = wcstombs(NULL, (const wchar_t *restrict)in_path_name, 0) + 1;
+
+ file_name = (char *)malloc(file_size * sizeof(char));
+ path_name = (char *)malloc(path_size * sizeof(char));
+
+ wcstoutf8(file_name, (__u16 *)in_file_name, file_size);
+ wcstoutf8(path_name, (__u16 *)in_path_name, path_size);
+
+ return hv_fcopy_create_file(file_name, path_name, smsg_in->copy_flags);
+}
+
+static int hv_fcopy_send_data(struct hv_fcopy_hdr *fcopy_msg, int recvlen)
+{
+ int operation = fcopy_msg->operation;
+
+ /*
+ * The strings sent from the host are encoded in
+ * utf16; convert it to utf8 strings.
+ * The host assures us that the utf16 strings will not exceed
+ * the max lengths specified. We will however, reserve room
+ * for the string terminating character - in the utf16s_utf8s()
+ * function we limit the size of the buffer where the converted
+ * string is placed to W_MAX_PATH -1 to guarantee
+ * that the strings can be properly terminated!
+ */
+
+ switch (operation) {
+ case START_FILE_COPY:
+ return hv_fcopy_start((struct hv_start_fcopy *)fcopy_msg);
+ case WRITE_TO_FILE:
+ return hv_copy_data((struct hv_do_fcopy *)fcopy_msg);
+ case COMPLETE_FCOPY:
+ return hv_copy_finished();
+ }
+
+ return HV_E_FAIL;
+}
+
+/* process the packet recv from host */
+static int fcopy_pkt_process(struct vmbus_br *txbr)
+{
+ int ret, offset, pktlen;
+ int fcopy_srv_version;
+ const struct vmbus_chanpkt_hdr *pkt;
+ struct hv_fcopy_hdr *fcopy_msg;
+ struct icmsg_hdr *icmsghdr;
+
+ pkt = (const struct vmbus_chanpkt_hdr *)desc;
+ offset = pkt->hlen << 3;
+ pktlen = (pkt->tlen << 3) - offset;
+ icmsghdr = (struct icmsg_hdr *)&desc[offset + sizeof(struct vmbuspipe_hdr)];
+ icmsghdr->status = HV_E_FAIL;
+
+ if (icmsghdr->icmsgtype == ICMSGTYPE_NEGOTIATE) {
+ if (vmbus_prep_negotiate_resp(icmsghdr, desc + offset, pktlen, fw_versions,
+ FW_VER_COUNT, fcopy_versions, FCOPY_VER_COUNT,
+ NULL, &fcopy_srv_version)) {
+ syslog(LOG_INFO, "FCopy IC version %d.%d",
+ fcopy_srv_version >> 16, fcopy_srv_version & 0xFFFF);
+ icmsghdr->status = 0;
+ }
+ } else if (icmsghdr->icmsgtype == ICMSGTYPE_FCOPY) {
+ /* Ensure recvlen is big enough to contain hv_fcopy_hdr */
+ if (pktlen < ICMSG_HDR + sizeof(struct hv_fcopy_hdr)) {
+ syslog(LOG_ERR, "Invalid Fcopy hdr. Packet length too small: %u",
+ pktlen);
+ return -ENOBUFS;
+ }
+
+ fcopy_msg = (struct hv_fcopy_hdr *)&desc[offset + ICMSG_HDR];
+ icmsghdr->status = hv_fcopy_send_data(fcopy_msg, pktlen);
+ }
+
+ icmsghdr->icflags = ICMSGHDRFLAG_TRANSACTION | ICMSGHDRFLAG_RESPONSE;
+ ret = rte_vmbus_chan_send(txbr, 0x6, desc + offset, pktlen, 0);
+ if (ret) {
+ syslog(LOG_ERR, "Write to ringbuffer failed err: %d", ret);
+ return ret;
+ }
+
+ return 0;
+}
+
+static void fcopy_get_first_folder(char *path, char *chan_no)
+{
+ DIR *dir = opendir(path);
+ struct dirent *entry;
+
+ if (!dir) {
+ syslog(LOG_ERR, "Failed to open directory (errno=%s).\n", strerror(errno));
+ return;
+ }
+
+ while ((entry = readdir(dir)) != NULL) {
+ if (entry->d_type == DT_DIR && strcmp(entry->d_name, ".") != 0 &&
+ strcmp(entry->d_name, "..") != 0) {
+ strcpy(chan_no, entry->d_name);
+ break;
+ }
+ }
+
+ closedir(dir);
+}
+
+int main(int argc, char *argv[])
+{
+ int fcopy_fd = -1, tmp = 1;
+ int daemonize = 1, long_index = 0, opt, ret = -EINVAL;
+ struct vmbus_br txbr, rxbr;
+ void *ring;
+ uint32_t len = HV_RING_SIZE;
+ char chan_no[MAX_FOLDER_NAME] = {0};
+ char uio_name[MAX_FOLDER_NAME] = {0};
+ char uio_dev_path[MAX_PATH_LEN] = {0};
+
+ static struct option long_options[] = {
+ {"help", no_argument, 0, 'h' },
+ {"no-daemon", no_argument, 0, 'n' },
+ {0, 0, 0, 0 }
+ };
+
+ while ((opt = getopt_long(argc, argv, "hn", long_options,
+ &long_index)) != -1) {
+ switch (opt) {
+ case 'n':
+ daemonize = 0;
+ break;
+ case 'h':
+ default:
+ print_usage(argv);
+ goto exit;
+ }
+ }
+
+ if (daemonize && daemon(1, 0)) {
+ syslog(LOG_ERR, "daemon() failed; error: %s", strerror(errno));
+ goto exit;
+ }
+
+ openlog("HV_UIO_FCOPY", 0, LOG_USER);
+ syslog(LOG_INFO, "starting; pid is:%d", getpid());
+
+ fcopy_get_first_folder(FCOPY_UIO, uio_name);
+ snprintf(uio_dev_path, sizeof(uio_dev_path), "/dev/%s", uio_name);
+ fcopy_fd = open(uio_dev_path, O_RDWR);
+
+ if (fcopy_fd < 0) {
+ syslog(LOG_ERR, "open %s failed; error: %d %s",
+ uio_dev_path, errno, strerror(errno));
+ ret = fcopy_fd;
+ goto exit;
+ }
+
+ fcopy_get_first_folder(FCOPY_SYSFS_CHAN, chan_no);
+ ring = vmbus_uio_map(FCOPY_SYSFS_CHAN, chan_no, HV_RING_SIZE);
+ if (!ring) {
+ ret = errno;
+ syslog(LOG_ERR, "mmap ringbuffer failed; error: %d %s", ret, strerror(ret));
+ goto close;
+ }
+ vmbus_br_setup(&txbr, ring, HV_RING_SIZE);
+ vmbus_br_setup(&rxbr, (char *)ring + HV_RING_SIZE, HV_RING_SIZE);
+
+ while (1) {
+ /*
+ * In this loop we process fcopy messages after the
+ * handshake is complete.
+ */
+ ret = pread(fcopy_fd, &tmp, sizeof(int), 0);
+ if (ret < 0) {
+ syslog(LOG_ERR, "pread failed: %s", strerror(errno));
+ continue;
+ }
+
+ len = HV_RING_SIZE;
+ ret = rte_vmbus_chan_recv_raw(&rxbr, desc, &len);
+ if (unlikely(ret <= 0)) {
+ /* This indicates a failure to communicate (or worse) */
+ syslog(LOG_ERR, "VMBus channel recv error: %d", ret);
+ } else {
+ ret = fcopy_pkt_process(&txbr);
+ if (ret < 0)
+ goto close;
+
+ /* Signal host */
+ if ((write(fcopy_fd, &tmp, sizeof(int))) != sizeof(int)) {
+ ret = errno;
+ syslog(LOG_ERR, "Registration failed: %s\n", strerror(ret));
+ goto close;
+ }
+ }
+ }
+close:
+ close(fcopy_fd);
+exit:
+ return ret;
+}
--
2.34.1
Generic VMBus driver that can be dynamically bound, to any simple
low speed Hyper-V VMBus device. This driver supports single
channel and uses hypercall instead of monitor bits to interrupt
host, which is suitable for low speed devices. Additionally, the
driver also provide the flexibility of custom ring buffer sizes and
avoid memory allocation for gpadl to offer memory optimization.
Signed-off-by: Saurabh Sengar <[email protected]>
---
drivers/uio/Kconfig | 12 ++
drivers/uio/Makefile | 1 +
drivers/uio/uio_hv_vmbus_client.c | 232 ++++++++++++++++++++++++++++++
3 files changed, 245 insertions(+)
create mode 100644 drivers/uio/uio_hv_vmbus_client.c
diff --git a/drivers/uio/Kconfig b/drivers/uio/Kconfig
index 2e16c5338e5b..dcc727e6fd3f 100644
--- a/drivers/uio/Kconfig
+++ b/drivers/uio/Kconfig
@@ -166,6 +166,18 @@ config UIO_HV_GENERIC
If you compile this as a module, it will be called uio_hv_generic.
+config UIO_HV_SLOW_DEVICES
+ tristate "Generic driver for low speed VMBus devices"
+ depends on HYPERV
+ help
+ Generic driver that you can bind, dynamically, to any simple
+ Hyper-V VMBus device with single channel and these devices
+ uses hypercall instead of monitor bits to interrupt host. This
+ driver also provide the flexibility of custom ring buffer sizes.
+ It is useful for slower VMbus devices.
+
+ If you compile this as a module, it will be called uio_hv_vmbus_client.
+
config UIO_DFL
tristate "Generic driver for DFL (Device Feature List) bus"
depends on FPGA_DFL
diff --git a/drivers/uio/Makefile b/drivers/uio/Makefile
index f2f416a14228..44be0f96da34 100644
--- a/drivers/uio/Makefile
+++ b/drivers/uio/Makefile
@@ -11,4 +11,5 @@ obj-$(CONFIG_UIO_PRUSS) += uio_pruss.o
obj-$(CONFIG_UIO_MF624) += uio_mf624.o
obj-$(CONFIG_UIO_FSL_ELBC_GPCM) += uio_fsl_elbc_gpcm.o
obj-$(CONFIG_UIO_HV_GENERIC) += uio_hv_generic.o
+obj-$(CONFIG_UIO_HV_SLOW_DEVICES) += uio_hv_vmbus_client.o
obj-$(CONFIG_UIO_DFL) += uio_dfl.o
diff --git a/drivers/uio/uio_hv_vmbus_client.c b/drivers/uio/uio_hv_vmbus_client.c
new file mode 100644
index 000000000000..a5a47caeffe1
--- /dev/null
+++ b/drivers/uio/uio_hv_vmbus_client.c
@@ -0,0 +1,232 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * uio_hv_vmbus_client - UIO driver for low speed VMBus devices
+ *
+ * Copyright (c) 2023, Microsoft Corporation.
+ *
+ * Authors:
+ * Saurabh Sengar <[email protected]>
+ *
+ * Since the driver does not declare any device ids, you must allocate
+ * id and bind the device to the driver yourself. For example:
+ * driverctl -b vmbus set-override <dev uuid> uio_hv_vmbus_client
+ */
+
+#include <linux/device.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/uio_driver.h>
+#include <linux/hyperv.h>
+#include <linux/vmalloc.h>
+#include <linux/sysfs.h>
+
+#define DRIVER_VERSION "0.0.1"
+#define DRIVER_AUTHOR "Saurabh Sengar <[email protected]>"
+#define DRIVER_DESC "Generic UIO driver for low speed VMBus devices"
+
+#define DEFAULT_HV_RING_SIZE VMBUS_RING_SIZE(3 * HV_HYP_PAGE_SIZE)
+static int ring_size = DEFAULT_HV_RING_SIZE;
+
+struct uio_hv_vmbus_dev {
+ struct uio_info info;
+ struct hv_device *device;
+ atomic_t refcnt;
+};
+
+/* Sysfs API to allow mmap of the ring buffers
+ * The ring buffer is allocated as contiguous memory by vmbus_open
+ */
+static int uio_hv_vmbus_mmap(struct file *filp, struct kobject *kobj,
+ struct bin_attribute *attr, struct vm_area_struct *vma)
+{
+ struct vmbus_channel *channel = container_of(kobj, struct vmbus_channel, kobj);
+ void *ring_buffer = page_address(channel->ringbuffer_page);
+
+ return vm_iomap_memory(vma, virt_to_phys(ring_buffer),
+ channel->ringbuffer_pagecount << PAGE_SHIFT);
+}
+
+static const struct bin_attribute ring_buffer_bin_attr = {
+ .attr = {
+ .name = "ringbuffer",
+ .mode = 0600,
+ },
+ .mmap = uio_hv_vmbus_mmap,
+};
+
+/*
+ * This is the irqcontrol callback to be registered to uio_info.
+ * It can be used to disable/enable interrupt from user space processes.
+ *
+ * @param info
+ * pointer to uio_info.
+ * @param irq_state
+ * state value. 1 to enable interrupt, 0 to disable interrupt.
+ */
+static int uio_hv_vmbus_irqcontrol(struct uio_info *info, s32 irq_state)
+{
+ struct uio_hv_vmbus_dev *pdata = info->priv;
+ struct hv_device *hv_dev = pdata->device;
+
+ /* Issue a full memory barrier before triggering the notification */
+ virt_mb();
+
+ vmbus_setevent(hv_dev->channel);
+ return 0;
+}
+
+/*
+ * Callback from vmbus_event when something is in inbound ring.
+ */
+static void uio_hv_vmbus_channel_cb(void *context)
+{
+ struct uio_hv_vmbus_dev *pdata = context;
+
+ /* Issue a full memory barrier before sending the event to userspace */
+ virt_mb();
+
+ uio_event_notify(&pdata->info);
+}
+
+static int uio_hv_vmbus_open(struct uio_info *info, struct inode *inode)
+{
+ struct uio_hv_vmbus_dev *pdata = container_of(info, struct uio_hv_vmbus_dev, info);
+ struct hv_device *hv_dev = pdata->device;
+ struct vmbus_channel *channel = hv_dev->channel;
+ int ret = 0;
+
+ if (atomic_inc_return(&pdata->refcnt) != 1)
+ return 0;
+
+ ret = vmbus_open(channel, ring_size, ring_size, NULL, 0,
+ uio_hv_vmbus_channel_cb, pdata);
+ if (ret) {
+ dev_err(&hv_dev->device, "error %d when opening the channel\n", ret);
+ goto done;
+ }
+ channel->inbound.ring_buffer->interrupt_mask = 0;
+ set_channel_read_mode(channel, HV_CALL_ISR);
+
+ ret = sysfs_create_bin_file(&channel->kobj, &ring_buffer_bin_attr);
+ if (ret)
+ dev_notice(&hv_dev->device, "sysfs create ring bin file failed; %d\n", ret);
+
+ return 0;
+
+done:
+ atomic_dec(&pdata->refcnt);
+ return ret;
+}
+
+/* VMbus primary channel is closed on last close */
+static int uio_hv_vmbus_release(struct uio_info *info, struct inode *inode)
+{
+ struct uio_hv_vmbus_dev *pdata = container_of(info, struct uio_hv_vmbus_dev, info);
+ struct hv_device *hv_dev = pdata->device;
+ struct vmbus_channel *channel = hv_dev->channel;
+
+ sysfs_remove_bin_file(&channel->kobj, &ring_buffer_bin_attr);
+
+ if (atomic_dec_and_test(&pdata->refcnt))
+ vmbus_close(channel);
+
+ return 0;
+}
+
+static ssize_t ring_size_show(struct device *dev, struct device_attribute *attr,
+ char *buf)
+{
+ return scnprintf(buf, PAGE_SIZE, "%d\n", ring_size);
+}
+
+static ssize_t ring_size_store(struct device *dev, struct device_attribute *attr,
+ const char *buf, size_t count)
+{
+ unsigned int val;
+
+ if (kstrtouint(buf, 0, &val) < 0)
+ return -EINVAL;
+
+ if (val < HV_HYP_PAGE_SIZE)
+ return -EINVAL;
+
+ ring_size = val;
+
+ return count;
+}
+static DEVICE_ATTR_RW(ring_size);
+
+static int uio_hv_vmbus_probe(struct hv_device *dev, const struct hv_vmbus_device_id *dev_id)
+{
+ struct uio_hv_vmbus_dev *pdata;
+ int ret = 0;
+ char *name = NULL;
+
+ pdata = devm_kzalloc(&dev->device, sizeof(*pdata), GFP_KERNEL);
+ if (!pdata)
+ return -ENOMEM;
+
+ name = kasprintf(GFP_KERNEL, "%pUl", &dev->dev_instance);
+
+ /* Fill general uio info */
+ pdata->info.name = name; /* /sys/class/uio/uioX/name */
+ pdata->info.version = DRIVER_VERSION;
+ pdata->info.irqcontrol = uio_hv_vmbus_irqcontrol;
+ pdata->info.open = uio_hv_vmbus_open;
+ pdata->info.release = uio_hv_vmbus_release;
+ pdata->info.irq = UIO_IRQ_CUSTOM;
+ pdata->info.priv = pdata;
+ pdata->device = dev;
+
+ ret = uio_register_device(&dev->device, &pdata->info);
+ if (ret) {
+ dev_err(&dev->device, "uio_hv_vmbus register failed\n");
+ goto fail;
+ }
+
+ ret = sysfs_create_file(&dev->device.kobj, &dev_attr_ring_size.attr);
+ if (ret)
+ dev_notice(&dev->device, "sysfs create ring size file failed; %d\n", ret);
+
+ hv_set_drvdata(dev, pdata);
+ return 0;
+
+fail:
+ kfree(pdata);
+ return ret;
+}
+
+static void
+uio_hv_vmbus_remove(struct hv_device *dev)
+{
+ struct uio_hv_vmbus_dev *pdata = hv_get_drvdata(dev);
+
+ sysfs_remove_file(&dev->device.kobj, &dev_attr_ring_size.attr);
+ if (pdata)
+ uio_unregister_device(&pdata->info);
+}
+
+static struct hv_driver uio_hv_vmbus_drv = {
+ .name = "uio_hv_vmbus_client",
+ .id_table = NULL, /* only dynamic id's */
+ .probe = uio_hv_vmbus_probe,
+ .remove = uio_hv_vmbus_remove,
+};
+
+static int __init uio_hv_vmbus_init(void)
+{
+ return vmbus_driver_register(&uio_hv_vmbus_drv);
+}
+
+static void __exit uio_hv_vmbus_exit(void)
+{
+ vmbus_driver_unregister(&uio_hv_vmbus_drv);
+}
+
+module_init(uio_hv_vmbus_init);
+module_exit(uio_hv_vmbus_exit);
+
+MODULE_VERSION(DRIVER_VERSION);
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR(DRIVER_AUTHOR);
+MODULE_DESCRIPTION(DRIVER_DESC);
--
2.34.1
Common userspace interface for read/write from VMBus ringbuffer.
This implementation is open for use by any userspace driver or
application seeking direct control over VMBus ring buffers.
A significant part of this code is borrowed from DPDK.
Link: https://github.com/DPDK/dpdk/
Signed-off-by: Saurabh Sengar <[email protected]>
---
tools/hv/vmbus_bufring.c | 324 +++++++++++++++++++++++++++++++++++++++
tools/hv/vmbus_bufring.h | 158 +++++++++++++++++++
2 files changed, 482 insertions(+)
create mode 100644 tools/hv/vmbus_bufring.c
create mode 100644 tools/hv/vmbus_bufring.h
diff --git a/tools/hv/vmbus_bufring.c b/tools/hv/vmbus_bufring.c
new file mode 100644
index 000000000000..eb61042f7605
--- /dev/null
+++ b/tools/hv/vmbus_bufring.c
@@ -0,0 +1,324 @@
+// SPDX-License-Identifier: BSD-3-Clause
+/*
+ * Copyright (c) 2009-2012,2016,2023 Microsoft Corp.
+ * Copyright (c) 2012 NetApp Inc.
+ * Copyright (c) 2012 Citrix Inc.
+ * All rights reserved.
+ */
+
+#include <errno.h>
+#include <fcntl.h>
+#include <emmintrin.h>
+#include <linux/limits.h>
+#include <stdbool.h>
+#include <stdint.h>
+#include <stdio.h>
+#include <string.h>
+#include <sys/mman.h>
+#include <sys/uio.h>
+#include <unistd.h>
+#include "vmbus_bufring.h"
+
+#define rte_compiler_barrier() ({ asm volatile ("" : : : "memory"); })
+
+#define rte_smp_rwmb() ({ asm volatile ("" : : : "memory"); })
+
+#define VMBUS_RQST_ERROR 0xFFFFFFFFFFFFFFFF
+#define ALIGN(val, align) ((typeof(val))((val) & (~((typeof(val))((align) - 1)))))
+
+void *vmbus_uio_map(char *sys_chan_path, char *chan_no, int size)
+{
+ void *map;
+ int fd;
+ char dirname[PATH_MAX];
+
+ snprintf(dirname, sizeof(dirname), "%s/%s/ringbuffer", sys_chan_path, chan_no);
+ fd = open(dirname, O_RDWR);
+ if (fd < 0)
+ return NULL;
+
+ map = mmap(NULL, 2 * size, PROT_READ | PROT_WRITE, MAP_SHARED, fd, 0);
+ close(fd);
+ if (map == MAP_FAILED)
+ return NULL;
+
+ return map;
+}
+
+/* Increase bufring index by inc with wraparound */
+static inline uint32_t vmbus_br_idxinc(uint32_t idx, uint32_t inc, uint32_t sz)
+{
+ idx += inc;
+ if (idx >= sz)
+ idx -= sz;
+
+ return idx;
+}
+
+void vmbus_br_setup(struct vmbus_br *br, void *buf, unsigned int blen)
+{
+ br->vbr = buf;
+ br->windex = br->vbr->windex;
+ br->dsize = blen - sizeof(struct vmbus_bufring);
+}
+
+static inline __always_inline void
+rte_smp_mb(void)
+{
+ asm volatile("lock addl $0, -128(%%rsp); " ::: "memory");
+}
+
+static inline int
+rte_atomic32_cmpset(volatile uint32_t *dst, uint32_t exp, uint32_t src)
+{
+ uint8_t res;
+
+ asm volatile("lock ; "
+ "cmpxchgl %[src], %[dst];"
+ "sete %[res];"
+ : [res] "=a" (res), /* output */
+ [dst] "=m" (*dst)
+ : [src] "r" (src), /* input */
+ "a" (exp),
+ "m" (*dst)
+ : "memory"); /* no-clobber list */
+ return res;
+}
+
+static inline uint32_t
+vmbus_txbr_copyto(const struct vmbus_br *tbr, uint32_t windex,
+ const void *src0, uint32_t cplen)
+{
+ uint8_t *br_data = tbr->vbr->data;
+ uint32_t br_dsize = tbr->dsize;
+ const uint8_t *src = src0;
+
+ /* XXX use double mapping like Linux kernel? */
+ if (cplen > br_dsize - windex) {
+ uint32_t fraglen = br_dsize - windex;
+
+ /* Wrap-around detected */
+ memcpy(br_data + windex, src, fraglen);
+ memcpy(br_data, src + fraglen, cplen - fraglen);
+ } else {
+ memcpy(br_data + windex, src, cplen);
+ }
+
+ return vmbus_br_idxinc(windex, cplen, br_dsize);
+}
+
+/*
+ * Write scattered channel packet to TX bufring.
+ *
+ * The offset of this channel packet is written as a 64bits value
+ * immediately after this channel packet.
+ *
+ * The write goes through three stages:
+ * 1. Reserve space in ring buffer for the new data.
+ * Writer atomically moves priv_write_index.
+ * 2. Copy the new data into the ring.
+ * 3. Update the tail of the ring (visible to host) that indicates
+ * next read location. Writer updates write_index
+ */
+static int
+vmbus_txbr_write(struct vmbus_br *tbr, const struct iovec iov[], int iovlen,
+ bool *need_sig)
+{
+ struct vmbus_bufring *vbr = tbr->vbr;
+ uint32_t ring_size = tbr->dsize;
+ uint32_t old_windex, next_windex, windex, total;
+ uint64_t save_windex;
+ int i;
+
+ total = 0;
+ for (i = 0; i < iovlen; i++)
+ total += iov[i].iov_len;
+ total += sizeof(save_windex);
+
+ /* Reserve space in ring */
+ do {
+ uint32_t avail;
+
+ /* Get current free location */
+ old_windex = tbr->windex;
+
+ /* Prevent compiler reordering this with calculation */
+ rte_compiler_barrier();
+
+ avail = vmbus_br_availwrite(tbr, old_windex);
+
+ /* If not enough space in ring, then tell caller. */
+ if (avail <= total)
+ return -EAGAIN;
+
+ next_windex = vmbus_br_idxinc(old_windex, total, ring_size);
+
+ /* Atomic update of next write_index for other threads */
+ } while (!rte_atomic32_cmpset(&tbr->windex, old_windex, next_windex));
+
+ /* Space from old..new is now reserved */
+ windex = old_windex;
+ for (i = 0; i < iovlen; i++)
+ windex = vmbus_txbr_copyto(tbr, windex, iov[i].iov_base, iov[i].iov_len);
+
+ /* Set the offset of the current channel packet. */
+ save_windex = ((uint64_t)old_windex) << 32;
+ windex = vmbus_txbr_copyto(tbr, windex, &save_windex,
+ sizeof(save_windex));
+
+ /* The region reserved should match region used */
+ if (windex != next_windex)
+ return -EINVAL;
+
+ /* Ensure that data is available before updating host index */
+ rte_smp_rwmb();
+
+ /* Checkin for our reservation. wait for our turn to update host */
+ while (!rte_atomic32_cmpset(&vbr->windex, old_windex, next_windex))
+ _mm_pause();
+
+ return 0;
+}
+
+int rte_vmbus_chan_send(struct vmbus_br *txbr, uint16_t type, void *data,
+ uint32_t dlen, uint32_t flags)
+{
+ struct vmbus_chanpkt pkt;
+ unsigned int pktlen, pad_pktlen;
+ const uint32_t hlen = sizeof(pkt);
+ bool send_evt = false;
+ uint64_t pad = 0;
+ struct iovec iov[3];
+ int error;
+
+ pktlen = hlen + dlen;
+ pad_pktlen = ALIGN(pktlen, sizeof(uint64_t));
+
+ pkt.hdr.type = type;
+ pkt.hdr.flags = flags;
+ pkt.hdr.hlen = hlen >> VMBUS_CHANPKT_SIZE_SHIFT;
+ pkt.hdr.tlen = pad_pktlen >> VMBUS_CHANPKT_SIZE_SHIFT;
+ pkt.hdr.xactid = VMBUS_RQST_ERROR;
+
+ iov[0].iov_base = &pkt;
+ iov[0].iov_len = hlen;
+ iov[1].iov_base = data;
+ iov[1].iov_len = dlen;
+ iov[2].iov_base = &pad;
+ iov[2].iov_len = pad_pktlen - pktlen;
+
+ error = vmbus_txbr_write(txbr, iov, 3, &send_evt);
+
+ return error;
+}
+
+static inline uint32_t
+vmbus_rxbr_copyfrom(const struct vmbus_br *rbr, uint32_t rindex,
+ void *dst0, size_t cplen)
+{
+ const uint8_t *br_data = rbr->vbr->data;
+ uint32_t br_dsize = rbr->dsize;
+ uint8_t *dst = dst0;
+
+ if (cplen > br_dsize - rindex) {
+ uint32_t fraglen = br_dsize - rindex;
+
+ /* Wrap-around detected. */
+ memcpy(dst, br_data + rindex, fraglen);
+ memcpy(dst + fraglen, br_data, cplen - fraglen);
+ } else {
+ memcpy(dst, br_data + rindex, cplen);
+ }
+
+ return vmbus_br_idxinc(rindex, cplen, br_dsize);
+}
+
+/* Copy data from receive ring but don't change index */
+static int
+vmbus_rxbr_peek(const struct vmbus_br *rbr, void *data, size_t dlen)
+{
+ uint32_t avail;
+
+ /*
+ * The requested data and the 64bits channel packet
+ * offset should be there at least.
+ */
+ avail = vmbus_br_availread(rbr);
+ if (avail < dlen + sizeof(uint64_t))
+ return -EAGAIN;
+
+ vmbus_rxbr_copyfrom(rbr, rbr->vbr->rindex, data, dlen);
+ return 0;
+}
+
+/*
+ * Copy data from receive ring and change index
+ * NOTE:
+ * We assume (dlen + skip) == sizeof(channel packet).
+ */
+static int
+vmbus_rxbr_read(struct vmbus_br *rbr, void *data, size_t dlen, size_t skip)
+{
+ struct vmbus_bufring *vbr = rbr->vbr;
+ uint32_t br_dsize = rbr->dsize;
+ uint32_t rindex;
+
+ if (vmbus_br_availread(rbr) < dlen + skip + sizeof(uint64_t))
+ return -EAGAIN;
+
+ /* Record where host was when we started read (for debug) */
+ rbr->windex = rbr->vbr->windex;
+
+ /*
+ * Copy channel packet from RX bufring.
+ */
+ rindex = vmbus_br_idxinc(rbr->vbr->rindex, skip, br_dsize);
+ rindex = vmbus_rxbr_copyfrom(rbr, rindex, data, dlen);
+
+ /*
+ * Discard this channel packet's 64bits offset, which is useless to us.
+ */
+ rindex = vmbus_br_idxinc(rindex, sizeof(uint64_t), br_dsize);
+
+ /* Update the read index _after_ the channel packet is fetched. */
+ rte_compiler_barrier();
+
+ vbr->rindex = rindex;
+
+ return 0;
+}
+
+int rte_vmbus_chan_recv_raw(struct vmbus_br *rxbr,
+ void *data, uint32_t *len)
+{
+ struct vmbus_chanpkt_hdr pkt;
+ uint32_t dlen, bufferlen = *len;
+ int error;
+
+ error = vmbus_rxbr_peek(rxbr, &pkt, sizeof(pkt));
+ if (error)
+ return error;
+
+ if (unlikely(pkt.hlen < VMBUS_CHANPKT_HLEN_MIN))
+ /* XXX this channel is dead actually. */
+ return -EIO;
+
+ if (unlikely(pkt.hlen > pkt.tlen))
+ return -EIO;
+
+ /* Length are in quad words */
+ dlen = pkt.tlen << VMBUS_CHANPKT_SIZE_SHIFT;
+ *len = dlen;
+
+ /* If caller buffer is not large enough */
+ if (unlikely(dlen > bufferlen))
+ return -ENOBUFS;
+
+ /* Read data and skip packet header */
+ error = vmbus_rxbr_read(rxbr, data, dlen, 0);
+ if (error)
+ return error;
+
+ /* Return the number of bytes read */
+ return dlen + sizeof(uint64_t);
+}
diff --git a/tools/hv/vmbus_bufring.h b/tools/hv/vmbus_bufring.h
new file mode 100644
index 000000000000..5ebe400132cc
--- /dev/null
+++ b/tools/hv/vmbus_bufring.h
@@ -0,0 +1,158 @@
+/* SPDX-License-Identifier: BSD-3-Clause */
+
+#ifndef _VMBUS_BUF_H_
+#define _VMBUS_BUF_H_
+
+#include <stdbool.h>
+#include <stdint.h>
+
+#define __packed __attribute__((__packed__))
+#define unlikely(x) __builtin_expect(!!(x), 0)
+
+#define ICMSGHDRFLAG_TRANSACTION 1
+#define ICMSGHDRFLAG_REQUEST 2
+#define ICMSGHDRFLAG_RESPONSE 4
+
+#define IC_VERSION_NEGOTIATION_MAX_VER_COUNT 100
+#define ICMSG_HDR (sizeof(struct vmbuspipe_hdr) + sizeof(struct icmsg_hdr))
+#define ICMSG_NEGOTIATE_PKT_SIZE(icframe_vercnt, icmsg_vercnt) \
+ (ICMSG_HDR + sizeof(struct icmsg_negotiate) + \
+ (((icframe_vercnt) + (icmsg_vercnt)) * sizeof(struct ic_version)))
+
+/*
+ * Channel packets
+ */
+
+/* Channel packet flags */
+#define VMBUS_CHANPKT_TYPE_INBAND 0x0006
+#define VMBUS_CHANPKT_TYPE_RXBUF 0x0007
+#define VMBUS_CHANPKT_TYPE_GPA 0x0009
+#define VMBUS_CHANPKT_TYPE_COMP 0x000b
+
+#define VMBUS_CHANPKT_FLAG_NONE 0
+#define VMBUS_CHANPKT_FLAG_RC 0x0001 /* report completion */
+
+#define VMBUS_CHANPKT_SIZE_SHIFT 3
+#define VMBUS_CHANPKT_SIZE_ALIGN BIT(VMBUS_CHANPKT_SIZE_SHIFT)
+#define VMBUS_CHANPKT_HLEN_MIN \
+ (sizeof(struct vmbus_chanpkt_hdr) >> VMBUS_CHANPKT_SIZE_SHIFT)
+
+/*
+ * Buffer ring
+ */
+struct vmbus_bufring {
+ volatile uint32_t windex;
+ volatile uint32_t rindex;
+
+ /*
+ * Interrupt mask {0,1}
+ *
+ * For TX bufring, host set this to 1, when it is processing
+ * the TX bufring, so that we can safely skip the TX event
+ * notification to host.
+ *
+ * For RX bufring, once this is set to 1 by us, host will not
+ * further dispatch interrupts to us, even if there are data
+ * pending on the RX bufring. This effectively disables the
+ * interrupt of the channel to which this RX bufring is attached.
+ */
+ volatile uint32_t imask;
+
+ /*
+ * Win8 uses some of the reserved bits to implement
+ * interrupt driven flow management. On the send side
+ * we can request that the receiver interrupt the sender
+ * when the ring transitions from being full to being able
+ * to handle a message of size "pending_send_sz".
+ *
+ * Add necessary state for this enhancement.
+ */
+ volatile uint32_t pending_send;
+ uint32_t reserved1[12];
+
+ union {
+ struct {
+ uint32_t feat_pending_send_sz:1;
+ };
+ uint32_t value;
+ } feature_bits;
+
+ /* Pad it to rte_mem_page_size() so that data starts on page boundary */
+ uint8_t reserved2[4028];
+
+ /*
+ * Ring data starts here + RingDataStartOffset
+ * !!! DO NOT place any fields below this !!!
+ */
+ uint8_t data[];
+} __packed;
+
+struct vmbus_br {
+ struct vmbus_bufring *vbr;
+ uint32_t dsize;
+ uint32_t windex; /* next available location */
+};
+
+struct vmbus_chanpkt_hdr {
+ uint16_t type; /* VMBUS_CHANPKT_TYPE_ */
+ uint16_t hlen; /* header len, in 8 bytes */
+ uint16_t tlen; /* total len, in 8 bytes */
+ uint16_t flags; /* VMBUS_CHANPKT_FLAG_ */
+ uint64_t xactid;
+} __packed;
+
+struct vmbus_chanpkt {
+ struct vmbus_chanpkt_hdr hdr;
+} __packed;
+
+struct vmbuspipe_hdr {
+ unsigned int flags;
+ unsigned int msgsize;
+} __packed;
+
+struct ic_version {
+ unsigned short major;
+ unsigned short minor;
+} __packed;
+
+struct icmsg_negotiate {
+ unsigned short icframe_vercnt;
+ unsigned short icmsg_vercnt;
+ unsigned int reserved;
+ struct ic_version icversion_data[]; /* any size array */
+} __packed;
+
+struct icmsg_hdr {
+ struct ic_version icverframe;
+ unsigned short icmsgtype;
+ struct ic_version icvermsg;
+ unsigned short icmsgsize;
+ unsigned int status;
+ unsigned char ictransaction_id;
+ unsigned char icflags;
+ unsigned char reserved[2];
+} __packed;
+
+int rte_vmbus_chan_recv_raw(struct vmbus_br *rxbr, void *data, uint32_t *len);
+int rte_vmbus_chan_send(struct vmbus_br *txbr, uint16_t type, void *data,
+ uint32_t dlen, uint32_t flags);
+void vmbus_br_setup(struct vmbus_br *br, void *buf, unsigned int blen);
+void *vmbus_uio_map(char *sys_dev_path, char *chan_no, int size);
+
+/* Amount of space available for write */
+static inline uint32_t vmbus_br_availwrite(const struct vmbus_br *br, uint32_t windex)
+{
+ uint32_t rindex = br->vbr->rindex;
+
+ if (windex >= rindex)
+ return br->dsize - (windex - rindex);
+ else
+ return rindex - windex;
+}
+
+static inline uint32_t vmbus_br_availread(const struct vmbus_br *br)
+{
+ return br->dsize - vmbus_br_availwrite(br, br->vbr->windex);
+}
+
+#endif /* !_VMBUS_BUF_H_ */
--
2.34.1
Hi Saurabh,
kernel test robot noticed the following build warnings:
[auto build test WARNING on char-misc/char-misc-testing]
[also build test WARNING on char-misc/char-misc-next char-misc/char-misc-linus linus/master v6.4-rc4 next-20230602]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch#_base_tree_information]
url: https://github.com/intel-lab-lkp/linux/commits/Saurabh-Sengar/uio-Add-hv_vmbus_client-driver/20230602-160029
base: char-misc/char-misc-testing
patch link: https://lore.kernel.org/r/1685692629-31351-2-git-send-email-ssengar%40linux.microsoft.com
patch subject: [PATCH 1/5] uio: Add hv_vmbus_client driver
config: i386-randconfig-c001-20230604 (https://download.01.org/0day-ci/archive/20230604/[email protected]/config)
compiler: gcc-12 (Debian 12.2.0-14) 12.2.0
If you fix the issue, kindly add following tag where applicable
| Reported-by: kernel test robot <[email protected]>
| Closes: https://lore.kernel.org/oe-kbuild-all/[email protected]/
cocci warnings: (new ones prefixed by >>)
>> drivers/uio/uio_hv_vmbus_client.c:195:1-6: WARNING: invalid free of devm_ allocated data
vim +195 drivers/uio/uio_hv_vmbus_client.c
158
159 static int uio_hv_vmbus_probe(struct hv_device *dev, const struct hv_vmbus_device_id *dev_id)
160 {
161 struct uio_hv_vmbus_dev *pdata;
162 int ret = 0;
163 char *name = NULL;
164
165 pdata = devm_kzalloc(&dev->device, sizeof(*pdata), GFP_KERNEL);
166 if (!pdata)
167 return -ENOMEM;
168
169 name = kasprintf(GFP_KERNEL, "%pUl", &dev->dev_instance);
170
171 /* Fill general uio info */
172 pdata->info.name = name; /* /sys/class/uio/uioX/name */
173 pdata->info.version = DRIVER_VERSION;
174 pdata->info.irqcontrol = uio_hv_vmbus_irqcontrol;
175 pdata->info.open = uio_hv_vmbus_open;
176 pdata->info.release = uio_hv_vmbus_release;
177 pdata->info.irq = UIO_IRQ_CUSTOM;
178 pdata->info.priv = pdata;
179 pdata->device = dev;
180
181 ret = uio_register_device(&dev->device, &pdata->info);
182 if (ret) {
183 dev_err(&dev->device, "uio_hv_vmbus register failed\n");
184 goto fail;
185 }
186
187 ret = sysfs_create_file(&dev->device.kobj, &dev_attr_ring_size.attr);
188 if (ret)
189 dev_notice(&dev->device, "sysfs create ring size file failed; %d\n", ret);
190
191 hv_set_drvdata(dev, pdata);
192 return 0;
193
194 fail:
> 195 kfree(pdata);
196 return ret;
197 }
198
--
0-DAY CI Kernel Test Service
https://github.com/intel/lkp-tests/wiki
On Fri, Jun 02, 2023 at 12:57:05AM -0700, Saurabh Sengar wrote:
> + * Since the driver does not declare any device ids, you must allocate
> + * id and bind the device to the driver yourself. For example:
> + * driverctl -b vmbus set-override <dev uuid> uio_hv_vmbus_client
Shouldn't this be documented somewhere?
> + */
> +
> +#include <linux/device.h>
> +#include <linux/kernel.h>
> +#include <linux/module.h>
> +#include <linux/uio_driver.h>
> +#include <linux/hyperv.h>
> +#include <linux/vmalloc.h>
> +#include <linux/sysfs.h>
> +
> +#define DRIVER_VERSION "0.0.1"
Why this number? Why not "1"?
The whole "driver version" thing doesn't really make sense here, we
should just drop it from the uio later, right?
> +#define DRIVER_AUTHOR "Saurabh Sengar <[email protected]>"
> +#define DRIVER_DESC "Generic UIO driver for low speed VMBus devices"
> +
> +#define DEFAULT_HV_RING_SIZE VMBUS_RING_SIZE(3 * HV_HYP_PAGE_SIZE)
> +static int ring_size = DEFAULT_HV_RING_SIZE;
> +
> +struct uio_hv_vmbus_dev {
> + struct uio_info info;
> + struct hv_device *device;
> + atomic_t refcnt;
Why is this refcnt needed?
Have you seen the other threads about how attempting to block multiple
opens in UIO drivers really does not work at all? Please drop all of
that logic, it is not correct.
> +static ssize_t ring_size_show(struct device *dev, struct device_attribute *attr,
> + char *buf)
> +{
> + return scnprintf(buf, PAGE_SIZE, "%d\n", ring_size);
Did you use checkpatch?
It should have said to use sysfs_emit(), right?
> + ret = sysfs_create_file(&dev->device.kobj, &dev_attr_ring_size.attr);
If you ever have to use a sysfs_* call in a driver, that's a huge hint
something is wrong. Please fix this to not race with userspace and
loose.
> + if (ret)
> + dev_notice(&dev->device, "sysfs create ring size file failed; %d\n", ret);
Why not just use dev_err() for this and other errors? Why "notice"?
> +MODULE_VERSION(DRIVER_VERSION);
This means nothing, please drop.
thanks,
greg k-h
> -----Original Message-----
> From: Greg KH <[email protected]>
> Sent: Sunday, June 4, 2023 12:40 PM
> To: Saurabh Sengar <[email protected]>
> Cc: KY Srinivasan <[email protected]>; Haiyang Zhang
> <[email protected]>; [email protected]; Dexuan Cui
> <[email protected]>; Michael Kelley (LINUX) <[email protected]>;
> [email protected]; [email protected]
> Subject: [EXTERNAL] Re: [PATCH 1/5] uio: Add hv_vmbus_client driver
>
> On Fri, Jun 02, 2023 at 12:57:05AM -0700, Saurabh Sengar wrote:
> > + * Since the driver does not declare any device ids, you must
> > + allocate
> > + * id and bind the device to the driver yourself. For example:
> > + * driverctl -b vmbus set-override <dev uuid> uio_hv_vmbus_client
>
> Shouldn't this be documented somewhere?
I will update it in Documentation/driver-api/uio-howto.rst.
>
> > + */
> > +
> > +#include <linux/device.h>
> > +#include <linux/kernel.h>
> > +#include <linux/module.h>
> > +#include <linux/uio_driver.h>
> > +#include <linux/hyperv.h>
> > +#include <linux/vmalloc.h>
> > +#include <linux/sysfs.h>
> > +
> > +#define DRIVER_VERSION "0.0.1"
>
> Why this number? Why not "1"?
>
> The whole "driver version" thing doesn't really make sense here, we should
> just drop it from the uio later, right?
will remove in V2.
>
> > +#define DRIVER_AUTHOR "Saurabh Sengar <[email protected]>"
> > +#define DRIVER_DESC "Generic UIO driver for low speed VMBus
> devices"
> > +
> > +#define DEFAULT_HV_RING_SIZE VMBUS_RING_SIZE(3 *
> HV_HYP_PAGE_SIZE)
> > +static int ring_size = DEFAULT_HV_RING_SIZE;
> > +
> > +struct uio_hv_vmbus_dev {
> > + struct uio_info info;
> > + struct hv_device *device;
> > + atomic_t refcnt;
>
> Why is this refcnt needed?
>
> Have you seen the other threads about how attempting to block multiple
> opens in UIO drivers really does not work at all? Please drop all of that logic,
> it is not correct.
>
Will remove.
>
> > +static ssize_t ring_size_show(struct device *dev, struct device_attribute
> *attr,
> > + char *buf)
> > +{
> > + return scnprintf(buf, PAGE_SIZE, "%d\n", ring_size);
>
> Did you use checkpatch?
>
> It should have said to use sysfs_emit(), right?
Yes, I am using "--strict" switch for checkpatch.pl, still didn't get this warning.
However, I will use sysfs_emit() in V2.
>
> > + ret = sysfs_create_file(&dev->device.kobj,
> > +&dev_attr_ring_size.attr);
>
> If you ever have to use a sysfs_* call in a driver, that's a huge hint something
> is wrong. Please fix this to not race with userspace and loose.
Thanks for pointing this out, will look into this.
>
> > + if (ret)
> > + dev_notice(&dev->device, "sysfs create ring size file failed;
> > +%d\n", ret);
>
> Why not just use dev_err() for this and other errors? Why "notice"?
Will fix.
>
> > +MODULE_VERSION(DRIVER_VERSION);
>
> This means nothing, please drop.
OK.
Thanks for review.
- Saurabh
>
> thanks,
>
> greg k-h