From efb339a83368ab25de1a18c0fdff85e01c13a1ea Mon Sep 17 00:00:00 2001 From: Peter Gonda Date: Tue, 7 Mar 2023 20:24:39 +0100 Subject: crypto: ccp - Name -1 return value as SEV_RET_NO_FW_CALL 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 Signed-off-by: Dionna Glaze Signed-off-by: Borislav Petkov (AMD) Link: https://lore.kernel.org/r/20221207010210.2563293-2-dionnaglaze@google.com --- include/uapi/linux/psp-sev.h | 7 +++++++ 1 file changed, 7 insertions(+) (limited to 'include/uapi/linux') diff --git a/include/uapi/linux/psp-sev.h b/include/uapi/linux/psp-sev.h index 91b4c63d5cbf..1c9da485318f 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, -- cgit v1.2.3 From 0144e3b85d7b42e8a4cda991c0e81f131897457a Mon Sep 17 00:00:00 2001 From: Dionna Glaze Date: Tue, 7 Mar 2023 20:24:49 +0100 Subject: x86/sev: Change snp_guest_issue_request()'s fw_err argument The GHCB specification declares that the firmware error value for a guest request will be stored in the lower 32 bits of EXIT_INFO_2. The upper 32 bits are for the VMM's own error code. The fw_err argument to snp_guest_issue_request() is thus a misnomer, and callers will need access to all 64 bits. The type of unsigned long also causes problems, since sw_exit_info2 is u64 (unsigned long long) vs the argument's unsigned long*. Change this type for issuing the guest request. Pass the ioctl command struct's error field directly instead of in a local variable, since an incomplete guest request may not set the error code, and uninitialized stack memory would be written back to user space. The firmware might not even be called, so bookend the call with the no firmware call error and clear the error. Since the "fw_err" field is really exitinfo2 split into the upper bits' vmm error code and lower bits' firmware error code, convert the 64 bit value to a union. [ bp: - Massage commit message - adjust code - Fix a build issue as Reported-by: kernel test robot Link: https://lore.kernel.org/oe-kbuild-all/202303070609.vX6wp2Af-lkp@intel.com - print exitinfo2 in hex Tom: - Correct -EIO exit case. ] Signed-off-by: Dionna Glaze Signed-off-by: Tom Lendacky Signed-off-by: Borislav Petkov (AMD) Link: https://lore.kernel.org/r/20230214164638.1189804-5-dionnaglaze@google.com Link: https://lore.kernel.org/r/20230307192449.24732-12-bp@alien8.de --- include/uapi/linux/sev-guest.h | 18 ++++++++++++++++-- 1 file changed, 16 insertions(+), 2 deletions(-) (limited to 'include/uapi/linux') diff --git a/include/uapi/linux/sev-guest.h b/include/uapi/linux/sev-guest.h index 256aaeff7e65..2aa39112cf8d 100644 --- a/include/uapi/linux/sev-guest.h +++ b/include/uapi/linux/sev-guest.h @@ -52,8 +52,14 @@ struct snp_guest_request_ioctl { __u64 req_data; __u64 resp_data; - /* firmware error code on failure (see psp-sev.h) */ - __u64 fw_err; + /* bits[63:32]: VMM error code, bits[31:0] firmware error code (see psp-sev.h) */ + union { + __u64 exitinfo2; + struct { + __u32 fw_error; + __u32 vmm_error; + }; + }; }; struct snp_ext_report_req { @@ -77,4 +83,12 @@ struct snp_ext_report_req { /* Get SNP extended report as defined in the GHCB specification version 2. */ #define SNP_GET_EXT_REPORT _IOWR(SNP_GUEST_REQ_IOC_TYPE, 0x2, struct snp_guest_request_ioctl) +/* Guest message request EXIT_INFO_2 constants */ +#define SNP_GUEST_FW_ERR_MASK GENMASK_ULL(31, 0) +#define SNP_GUEST_VMM_ERR_SHIFT 32 +#define SNP_GUEST_VMM_ERR(x) (((u64)x) << SNP_GUEST_VMM_ERR_SHIFT) + +#define SNP_GUEST_VMM_ERR_INVALID_LEN 1 +#define SNP_GUEST_VMM_ERR_BUSY 2 + #endif /* __UAPI_LINUX_SEV_GUEST_H_ */ -- cgit v1.2.3