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From:   Alexandre Chartre <alexandre.chartre@oracle.com>
To:     tglx@linutronix.de, mingo@redhat.com, bp@alien8.de, hpa@zytor.com,
        dave.hansen@linux.intel.com, luto@kernel.org, peterz@infradead.org,
        x86@kernel.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org
Cc:     pbonzini@redhat.com, konrad.wilk@oracle.com,
        jan.setjeeilers@oracle.com, liran.alon@oracle.com,
        junaids@google.com, graf@amazon.de, rppt@linux.vnet.ibm.com,
        kuzuno@gmail.com, mgross@linux.intel.com,
        alexandre.chartre@oracle.com
Subject: [RFC v4][PATCH part-3 10/14] asidrv: Add ioctls to manage ASI mapped VA ranges
Date:   Mon,  4 May 2020 17:02:31 +0200
Message-Id: <20200504150235.12171-11-alexandre.chartre@oracle.com>
In-Reply-To: <20200504150235.12171-1-alexandre.chartre@oracle.com>
References: <20200504150235.12171-1-alexandre.chartre@oracle.com>
Sender: linux-kernel-owner@vger.kernel.org
Precedence: bulk

Add ioctls to list, add, clear ASI mapped VA ranges.

Signed-off-by: Alexandre Chartre <alexandre.chartre@oracle.com>
---
 drivers/staging/asi/asidrv.c | 138 +++++++++++++++++++++++++++++++++++
 drivers/staging/asi/asidrv.h |  26 +++++++
 2 files changed, 164 insertions(+)

diff --git a/drivers/staging/asi/asidrv.c b/drivers/staging/asi/asidrv.c
index e6edfbe5acea..9d9784629833 100644
--- a/drivers/staging/asi/asidrv.c
+++ b/drivers/staging/asi/asidrv.c
@@ -866,10 +866,137 @@ static int asidrv_ioctl_log_fault_stack(struct asi *asi, bool log_stack)
 	return 0;
 }
 
+/*
+ * ASI decorated pagetable ioctls
+ */
+
+static int asidrv_ioctl_add_mapping(struct dpt *dpt, unsigned long arg)
+{
+	struct asidrv_mapping_list __user *umlist;
+	struct asidrv_mapping mapping;
+	__u32 umlist_len;
+	int i, err;
+
+	umlist = (struct asidrv_mapping_list *)arg;
+	if (copy_from_user(&umlist_len, &umlist->length, sizeof(umlist_len)))
+		return -EFAULT;
+
+	err = 0;
+	for (i = 0; i < umlist_len; i++) {
+		if (copy_from_user(&mapping, &umlist->mapping[i],
+				   sizeof(mapping))) {
+			err = -EFAULT;
+			break;
+		}
+
+		pr_debug("add mapping %llx/%llx/%u %s\n",
+			 mapping.addr, mapping.size, mapping.level,
+			 mapping.percpu ? "percpu" : "");
+
+		if (mapping.percpu) {
+			if (mapping.level != PGT_LEVEL_PTE) {
+				err = -EINVAL;
+				break;
+			}
+			err = dpt_map_percpu(dpt, (void *)mapping.addr,
+					     mapping.size);
+		} else {
+			err = dpt_map_range(dpt, (void *)mapping.addr,
+					    mapping.size, mapping.level);
+		}
+		if (err)
+			break;
+	}
+
+	if (err)
+		return (i == 0) ? err : i;
+
+	return 0;
+}
+
+static int asidrv_ioctl_clear_mapping(struct dpt *dpt, unsigned long arg)
+{
+	struct asidrv_mapping_list __user *umlist;
+	struct asidrv_mapping mapping;
+	__u32 umlist_len;
+	int err, i;
+
+	umlist = (struct asidrv_mapping_list *)arg;
+	if (copy_from_user(&umlist_len, &umlist->length, sizeof(umlist_len)))
+		return -EFAULT;
+
+	err = 0;
+	for (i = 0; i < umlist_len; i++) {
+		if (copy_from_user(&mapping, &umlist->mapping[i],
+				   sizeof(mapping))) {
+			err = -EFAULT;
+			break;
+		}
+
+		pr_debug("clear mapping %llx %s\n",
+			 mapping.addr, mapping.percpu ? "percpu" : "");
+
+		if (mapping.percpu)
+			dpt_unmap_percpu(dpt, (void *)mapping.addr);
+		else
+			dpt_unmap(dpt, (void *)mapping.addr);
+	}
+
+	if (err)
+		return (i == 0) ? err : i;
+
+	return 0;
+}
+
+static int asidrv_ioctl_list_mapping(struct dpt *dpt, unsigned long arg)
+{
+	struct asidrv_mapping_list __user *umlist;
+	struct asidrv_mapping_list *mlist;
+	struct dpt_range_mapping *range;
+	unsigned long addr;
+	size_t mlist_size;
+	__u32 umlist_len;
+	int i;
+
+	umlist = (struct asidrv_mapping_list *)arg;
+	if (copy_from_user(&umlist_len, &umlist->length, sizeof(umlist_len)))
+		return -EFAULT;
+
+	umlist_len = min_t(unsigned int, umlist_len, 512);
+
+	mlist_size = sizeof(*mlist) +
+		sizeof(struct asidrv_mapping) * umlist_len;
+	mlist = kzalloc(mlist_size, GFP_KERNEL);
+	if (!mlist)
+		return -ENOMEM;
+
+	i = 0;
+	list_for_each_entry(range, &dpt->mapping_list, list) {
+		if (i < umlist_len) {
+			addr = (__u64)range->ptr;
+			mlist->mapping[i].addr = addr;
+			mlist->mapping[i].size = range->size;
+			mlist->mapping[i].level = range->level;
+		}
+		i++;
+	}
+	mlist->length = i;
+
+	if (copy_to_user(umlist, mlist, mlist_size)) {
+		kfree(mlist);
+		return -EFAULT;
+	}
+
+	kfree(mlist);
+
+	return 0;
+}
+
 static long asidrv_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
 {
 	struct asidrv_test *test = asidrv_test;
 	struct asi *asi = test->asi;
+	struct dpt *dpt = test->dpt;
 
 	switch (cmd) {
 
@@ -884,6 +1011,17 @@ static long asidrv_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
 	case ASIDRV_IOCTL_LOG_FAULT_STACK:
 		return asidrv_ioctl_log_fault_stack(asi, arg);
 
+	/* ASI decorated pagetable ioctls */
+
+	case ASIDRV_IOCTL_LIST_MAPPING:
+		return asidrv_ioctl_list_mapping(dpt, arg);
+
+	case ASIDRV_IOCTL_ADD_MAPPING:
+		return asidrv_ioctl_add_mapping(dpt, arg);
+
+	case ASIDRV_IOCTL_CLEAR_MAPPING:
+		return asidrv_ioctl_clear_mapping(dpt, arg);
+
 	/* Test ioctls */
 
 	case ASIDRV_IOCTL_RUN_SEQUENCE:
diff --git a/drivers/staging/asi/asidrv.h b/drivers/staging/asi/asidrv.h
index 99ab9843e36b..f042106419db 100644
--- a/drivers/staging/asi/asidrv.h
+++ b/drivers/staging/asi/asidrv.h
@@ -48,6 +48,20 @@ enum asidrv_run_error {
 #define ASIDRV_IOCTL_CLEAR_FAULT	_IO('a', 3)
 #define ASIDRV_IOCTL_LOG_FAULT_STACK	_IO('a', 4)
 
+/*
+ * ASIDRV_IOCTL_ADD_MAPPING: add mapping to the ASI.
+ *
+ * User should set 'length' with the number of mapping described in the
+ * 'mapping' array.
+ * Return value:
+ *   -1   - error no mapping was added
+ *    0   - no error, all mappings were added
+ *   N>0  - error but the first N mappings were added
+ */
+#define ASIDRV_IOCTL_ADD_MAPPING	_IOWR('a', 5, struct asidrv_mapping_list)
+#define ASIDRV_IOCTL_CLEAR_MAPPING	_IOW('a', 6, struct asidrv_mapping_list)
+#define ASIDRV_IOCTL_LIST_MAPPING	_IOWR('a', 7, struct asidrv_mapping_list)
+
 #define ASIDRV_KSYM_NAME_LEN	128
 /*
  * We need KSYM_SYMBOL_LEN to lookup symbol. However it's not part of
@@ -73,4 +87,16 @@ struct asidrv_fault_list {
 	struct asidrv_fault fault[0];
 };
 
+struct asidrv_mapping {
+	__u64 addr;
+	__u64 size;
+	__u32 level;
+	__u32 percpu;
+};
+
+struct asidrv_mapping_list {
+	__u32 length;
+	struct asidrv_mapping mapping[0];
+};
+
 #endif
-- 
2.18.2