6.1-stable review patch. If anyone has any objections, please let me know.
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From: Peter Gonda pgonda@google.com
[ Upstream commit efb339a83368ab25de1a18c0fdff85e01c13a1ea ]
The PSP can return a "firmware error" code of -1 in circumstances where the PSP has not actually been called. To make this protocol unambiguous, name the value SEV_RET_NO_FW_CALL.
[ bp: Massage a bit. ]
Signed-off-by: Peter Gonda pgonda@google.com Signed-off-by: Dionna Glaze dionnaglaze@google.com Signed-off-by: Borislav Petkov (AMD) bp@alien8.de Link: https://lore.kernel.org/r/20221207010210.2563293-2-dionnaglaze@google.com Stable-dep-of: db10cb9b5746 ("virt: sevguest: Fix passing a stack buffer as a scatterlist target") Signed-off-by: Sasha Levin sashal@kernel.org --- Documentation/virt/coco/sev-guest.rst | 4 ++-- drivers/crypto/ccp/sev-dev.c | 8 +++++--- include/uapi/linux/psp-sev.h | 7 +++++++ 3 files changed, 14 insertions(+), 5 deletions(-)
diff --git a/Documentation/virt/coco/sev-guest.rst b/Documentation/virt/coco/sev-guest.rst index bf593e88cfd9d..aa3e4c6a1f90c 100644 --- a/Documentation/virt/coco/sev-guest.rst +++ b/Documentation/virt/coco/sev-guest.rst @@ -40,8 +40,8 @@ along with a description: The guest ioctl should be issued on a file descriptor of the /dev/sev-guest device. The ioctl accepts struct snp_user_guest_request. The input and output structure is specified through the req_data and resp_data field respectively. If the ioctl fails -to execute due to a firmware error, then fw_err code will be set otherwise the -fw_err will be set to 0x00000000000000ff. +to execute due to a firmware error, then fw_err code will be set. Otherwise, fw_err +will be set to 0x00000000ffffffff, i.e., the lower 32-bits are -1.
The firmware checks that the message sequence counter is one greater than the guests message sequence counter. If guest driver fails to increment message diff --git a/drivers/crypto/ccp/sev-dev.c b/drivers/crypto/ccp/sev-dev.c index 3e583f0324874..b8e02c3a19610 100644 --- a/drivers/crypto/ccp/sev-dev.c +++ b/drivers/crypto/ccp/sev-dev.c @@ -443,10 +443,10 @@ static int __sev_init_ex_locked(int *error)
static int __sev_platform_init_locked(int *error) { + int rc = 0, psp_ret = SEV_RET_NO_FW_CALL; struct psp_device *psp = psp_master; - struct sev_device *sev; - int rc = 0, psp_ret = -1; int (*init_function)(int *error); + struct sev_device *sev;
if (!psp || !psp->sev_data) return -ENODEV; @@ -474,9 +474,11 @@ static int __sev_platform_init_locked(int *error) * initialization function should succeed by replacing the state * with a reset state. */ - dev_err(sev->dev, "SEV: retrying INIT command because of SECURE_DATA_INVALID error. Retrying once to reset PSP SEV state."); + dev_err(sev->dev, +"SEV: retrying INIT command because of SECURE_DATA_INVALID error. Retrying once to reset PSP SEV state."); rc = init_function(&psp_ret); } + if (error) *error = psp_ret;
diff --git a/include/uapi/linux/psp-sev.h b/include/uapi/linux/psp-sev.h index 91b4c63d5cbf4..1c9da485318f9 100644 --- a/include/uapi/linux/psp-sev.h +++ b/include/uapi/linux/psp-sev.h @@ -36,6 +36,13 @@ enum { * SEV Firmware status code */ typedef enum { + /* + * This error code is not in the SEV spec. Its purpose is to convey that + * there was an error that prevented the SEV firmware from being called. + * The SEV API error codes are 16 bits, so the -1 value will not overlap + * with possible values from the specification. + */ + SEV_RET_NO_FW_CALL = -1, SEV_RET_SUCCESS = 0, SEV_RET_INVALID_PLATFORM_STATE, SEV_RET_INVALID_GUEST_STATE,