The command is used for copying the incoming buffer into the
SEV guest memory space.
Cc: Thomas Gleixner <[email protected]>
Cc: Ingo Molnar <[email protected]>
Cc: "H. Peter Anvin" <[email protected]>
Cc: Paolo Bonzini <[email protected]>
Cc: "Radim Krčmář" <[email protected]>
Cc: Joerg Roedel <[email protected]>
Cc: Borislav Petkov <[email protected]>
Cc: Tom Lendacky <[email protected]>
Cc: [email protected]
Cc: [email protected]
Cc: [email protected]
Signed-off-by: Brijesh Singh <[email protected]>
---
.../virtual/kvm/amd-memory-encryption.rst | 24 ++++++
arch/x86/kvm/svm.c | 75 +++++++++++++++++++
include/uapi/linux/kvm.h | 9 +++
3 files changed, 108 insertions(+)
diff --git a/Documentation/virtual/kvm/amd-memory-encryption.rst b/Documentation/virtual/kvm/amd-memory-encryption.rst
index 59a7903f7c4e..f0ec0cbe2aaf 100644
--- a/Documentation/virtual/kvm/amd-memory-encryption.rst
+++ b/Documentation/virtual/kvm/amd-memory-encryption.rst
@@ -326,6 +326,30 @@ On success, the 'handle' field contains a new handle and on error, a negative va
For more details, see SEV spec Section 6.12.
+14. KVM_SEV_RECEIVE_UPDATE_DATA
+----------------------------
+
+The KVM_SEV_RECEIVE_UPDATE_DATA command can be used by the hypervisor to copy
+the incoming buffers into the guest memory region with encryption context
+created during the KVM_SEV_RECEIVE_START.
+
+Parameters (in): struct kvm_sev_receive_update_data
+
+Returns: 0 on success, -negative on error
+
+::
+
+ struct kvm_sev_launch_receive_update_data {
+ __u64 hdr_uaddr; /* userspace address containing the packet header */
+ __u32 hdr_len;
+
+ __u64 guest_uaddr; /* the destination guest memory region */
+ __u32 guest_len;
+
+ __u64 trans_uaddr; /* the incoming buffer memory region */
+ __u32 trans_len;
+ };
+
References
==========
diff --git a/arch/x86/kvm/svm.c b/arch/x86/kvm/svm.c
index fae6a870b29a..ea084716f966 100644
--- a/arch/x86/kvm/svm.c
+++ b/arch/x86/kvm/svm.c
@@ -7265,6 +7265,78 @@ static int sev_receive_start(struct kvm *kvm, struct kvm_sev_cmd *argp)
return ret;
}
+static int sev_receive_update_data(struct kvm *kvm, struct kvm_sev_cmd *argp)
+{
+ struct kvm_sev_info *sev = &to_kvm_svm(kvm)->sev_info;
+ struct kvm_sev_receive_update_data params;
+ struct sev_data_receive_update_data *data;
+ void *hdr = NULL, *trans = NULL;
+ struct page **guest_page;
+ unsigned long n;
+ int ret, offset;
+
+ if (!sev_guest(kvm))
+ return -EINVAL;
+
+ if (copy_from_user(¶ms, (void __user *)(uintptr_t)argp->data,
+ sizeof(struct kvm_sev_receive_update_data)))
+ return -EFAULT;
+
+ if (!params.hdr_uaddr || !params.hdr_len ||
+ !params.guest_uaddr || !params.guest_len ||
+ !params.trans_uaddr || !params.trans_len)
+ return -EINVAL;
+
+ /* Check if we are crossing the page boundry */
+ offset = params.guest_uaddr & (PAGE_SIZE - 1);
+ if ((params.guest_len + offset > PAGE_SIZE))
+ return -EINVAL;
+
+ data = kzalloc(sizeof(*data), GFP_KERNEL);
+ if (!data)
+ return -ENOMEM;
+
+ hdr = psp_copy_user_blob(params.hdr_uaddr, params.hdr_len);
+ if (IS_ERR(hdr)) {
+ ret = PTR_ERR(hdr);
+ goto e_free;
+ }
+
+ data->hdr_address = __psp_pa(hdr);
+ data->hdr_len = params.hdr_len;
+
+ trans = psp_copy_user_blob(params.trans_uaddr, params.trans_len);
+ if (IS_ERR(trans)) {
+ ret = PTR_ERR(trans);
+ goto e_free;
+ }
+
+ data->trans_address = __psp_pa(trans);
+ data->trans_len = params.trans_len;
+
+ /* Pin guest memory */
+ ret = -EFAULT;
+ guest_page = sev_pin_memory(kvm, params.guest_uaddr & PAGE_MASK,
+ PAGE_SIZE, &n, 0);
+ if (!guest_page)
+ goto e_free;
+
+ /* The RECEIVE_UPDATE_DATA command requires C-bit to be always set. */
+ data->guest_address = (page_to_pfn(guest_page[0]) << PAGE_SHIFT) + offset;
+ data->guest_address |= sev_me_mask;
+ data->guest_len = params.guest_len;
+
+ data->handle = sev->handle;
+ ret = sev_issue_cmd(kvm, SEV_CMD_RECEIVE_UPDATE_DATA, data, &argp->error);
+
+ sev_unpin_memory(kvm, guest_page, n);
+e_free:
+ kfree(data);
+ kfree(hdr);
+ kfree(trans);
+ return ret;
+}
+
static int svm_mem_enc_op(struct kvm *kvm, void __user *argp)
{
struct kvm_sev_cmd sev_cmd;
@@ -7318,6 +7390,9 @@ static int svm_mem_enc_op(struct kvm *kvm, void __user *argp)
case KVM_SEV_RECEIVE_START:
r = sev_receive_start(kvm, &sev_cmd);
break;
+ case KVM_SEV_RECEIVE_UPDATE_DATA:
+ r = sev_receive_update_data(kvm, &sev_cmd);
+ break;
default:
r = -EINVAL;
goto out;
diff --git a/include/uapi/linux/kvm.h b/include/uapi/linux/kvm.h
index 28d240974ea7..e31cdb41519f 100644
--- a/include/uapi/linux/kvm.h
+++ b/include/uapi/linux/kvm.h
@@ -1561,6 +1561,15 @@ struct kvm_sev_receive_start {
__u32 session_len;
};
+struct kvm_sev_receive_update_data {
+ __u64 hdr_uaddr;
+ __u32 hdr_len;
+ __u64 guest_uaddr;
+ __u32 guest_len;
+ __u64 trans_uaddr;
+ __u32 trans_len;
+};
+
#define KVM_DEV_ASSIGN_ENABLE_IOMMU (1 << 0)
#define KVM_DEV_ASSIGN_PCI_2_3 (1 << 1)
#define KVM_DEV_ASSIGN_MASK_INTX (1 << 2)
--
2.17.1
On Wed, Jul 10, 2019 at 08:13:06PM +0000, Singh, Brijesh wrote:
> The command is used for copying the incoming buffer into the
> SEV guest memory space.
...
> +static int sev_receive_update_data(struct kvm *kvm, struct kvm_sev_cmd *argp)
> +{
> + struct kvm_sev_info *sev = &to_kvm_svm(kvm)->sev_info;
> + struct kvm_sev_receive_update_data params;
> + struct sev_data_receive_update_data *data;
> + void *hdr = NULL, *trans = NULL;
> + struct page **guest_page;
> + unsigned long n;
> + int ret, offset;
> +
> + if (!sev_guest(kvm))
> + return -EINVAL;
> +
> + if (copy_from_user(¶ms, (void __user *)(uintptr_t)argp->data,
> + sizeof(struct kvm_sev_receive_update_data)))
> + return -EFAULT;
> +
> + if (!params.hdr_uaddr || !params.hdr_len ||
> + !params.guest_uaddr || !params.guest_len ||
> + !params.trans_uaddr || !params.trans_len)
> + return -EINVAL;
> +
> + /* Check if we are crossing the page boundry */
WARNING: 'boundry' may be misspelled - perhaps 'boundary'?
> + offset = params.guest_uaddr & (PAGE_SIZE - 1);
> + if ((params.guest_len + offset > PAGE_SIZE))
> + return -EINVAL;
> +
> + data = kzalloc(sizeof(*data), GFP_KERNEL);
> + if (!data)
> + return -ENOMEM;
> +
> + hdr = psp_copy_user_blob(params.hdr_uaddr, params.hdr_len);
> + if (IS_ERR(hdr)) {
> + ret = PTR_ERR(hdr);
> + goto e_free;
> + }
> +
> + data->hdr_address = __psp_pa(hdr);
> + data->hdr_len = params.hdr_len;
> +
> + trans = psp_copy_user_blob(params.trans_uaddr, params.trans_len);
> + if (IS_ERR(trans)) {
> + ret = PTR_ERR(trans);
> + goto e_free;
> + }
> +
> + data->trans_address = __psp_pa(trans);
> + data->trans_len = params.trans_len;
> +
> + /* Pin guest memory */
> + ret = -EFAULT;
> + guest_page = sev_pin_memory(kvm, params.guest_uaddr & PAGE_MASK,
> + PAGE_SIZE, &n, 0);
> + if (!guest_page)
> + goto e_free;
> +
> + /* The RECEIVE_UPDATE_DATA command requires C-bit to be always set. */
> + data->guest_address = (page_to_pfn(guest_page[0]) << PAGE_SHIFT) + offset;
> + data->guest_address |= sev_me_mask;
> + data->guest_len = params.guest_len;
> +
> + data->handle = sev->handle;
> + ret = sev_issue_cmd(kvm, SEV_CMD_RECEIVE_UPDATE_DATA, data, &argp->error);
> +
> + sev_unpin_memory(kvm, guest_page, n);
> +e_free:
> + kfree(data);
> + kfree(hdr);
> + kfree(trans);
Pls add separate labels so that you don't have to init function-local
vars above to NULL.
--
Regards/Gruss,
Boris.
SUSE Software Solutions Germany GmbH, GF: Felix Imendörffer, HRB 247165, AG München
> +
> + /* Check if we are crossing the page boundry */
> + offset = params.guest_uaddr & (PAGE_SIZE - 1);
> + if ((params.guest_len + offset > PAGE_SIZE))
> + return -EINVAL;
Just curious spec only says that "System physical of the guest memory
region. Must be 16 B aligned with the C-bit set." and "Length of guest
memory region. Must be a multiple of 16 B and no more than 16 kB". Why
do we want to avoid crossing a page boundary?
Also is there an overflow concern in the conditional because
params.guest_len is not checked before this?
> +
> + data = kzalloc(sizeof(*data), GFP_KERNEL);
> + if (!data)
> + return -ENOMEM;
> +
> + hdr = psp_copy_user_blob(params.hdr_uaddr, params.hdr_len);
> + if (IS_ERR(hdr)) {
> + ret = PTR_ERR(hdr);
> + goto e_free;
> + }
> +