diff options
author | Dionna Glaze <dionnaglaze@google.com> | 2023-03-07 22:24:49 +0300 |
---|---|---|
committer | Borislav Petkov (AMD) <bp@alien8.de> | 2023-03-21 17:43:19 +0300 |
commit | 0144e3b85d7b42e8a4cda991c0e81f131897457a (patch) | |
tree | 370da06d54b94dc09f10e81accd0b2f403af16eb /arch | |
parent | 965006103a14703cc42043bbf9b5e0cdf7a468ad (diff) | |
download | linux-0144e3b85d7b42e8a4cda991c0e81f131897457a.tar.xz |
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 <lkp@intel.com>
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 <dionnaglaze@google.com>
Signed-off-by: Tom Lendacky <thomas.lendacky@amd.com>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Link: https://lore.kernel.org/r/20230214164638.1189804-5-dionnaglaze@google.com
Link: https://lore.kernel.org/r/20230307192449.24732-12-bp@alien8.de
Diffstat (limited to 'arch')
-rw-r--r-- | arch/x86/include/asm/sev-common.h | 4 | ||||
-rw-r--r-- | arch/x86/include/asm/sev.h | 10 | ||||
-rw-r--r-- | arch/x86/kernel/sev.c | 15 |
3 files changed, 15 insertions, 14 deletions
diff --git a/arch/x86/include/asm/sev-common.h b/arch/x86/include/asm/sev-common.h index b63be696b776..0759af9b1acf 100644 --- a/arch/x86/include/asm/sev-common.h +++ b/arch/x86/include/asm/sev-common.h @@ -128,10 +128,6 @@ struct snp_psc_desc { struct psc_entry entries[VMGEXIT_PSC_MAX_ENTRY]; } __packed; -/* Guest message request error codes */ -#define SNP_GUEST_REQ_INVALID_LEN BIT_ULL(32) -#define SNP_GUEST_REQ_ERR_BUSY BIT_ULL(33) - #define GHCB_MSR_TERM_REQ 0x100 #define GHCB_MSR_TERM_REASON_SET_POS 12 #define GHCB_MSR_TERM_REASON_SET_MASK 0xf diff --git a/arch/x86/include/asm/sev.h b/arch/x86/include/asm/sev.h index ebc271bb6d8e..13dc2a9d23c1 100644 --- a/arch/x86/include/asm/sev.h +++ b/arch/x86/include/asm/sev.h @@ -9,6 +9,8 @@ #define __ASM_ENCRYPTED_STATE_H #include <linux/types.h> +#include <linux/sev-guest.h> + #include <asm/insn.h> #include <asm/sev-common.h> #include <asm/bootparam.h> @@ -185,6 +187,9 @@ static inline int pvalidate(unsigned long vaddr, bool rmp_psize, bool validate) return rc; } + +struct snp_guest_request_ioctl; + void setup_ghcb(void); void __init early_snp_set_memory_private(unsigned long vaddr, unsigned long paddr, unsigned int npages); @@ -196,7 +201,7 @@ void snp_set_memory_private(unsigned long vaddr, unsigned int npages); void snp_set_wakeup_secondary_cpu(void); bool snp_init(struct boot_params *bp); void __init __noreturn snp_abort(void); -int snp_issue_guest_request(u64 exit_code, struct snp_req_data *input, unsigned long *fw_err); +int snp_issue_guest_request(u64 exit_code, struct snp_req_data *input, struct snp_guest_request_ioctl *rio); #else static inline void sev_es_ist_enter(struct pt_regs *regs) { } static inline void sev_es_ist_exit(void) { } @@ -216,8 +221,7 @@ static inline void snp_set_memory_private(unsigned long vaddr, unsigned int npag static inline void snp_set_wakeup_secondary_cpu(void) { } static inline bool snp_init(struct boot_params *bp) { return false; } static inline void snp_abort(void) { } -static inline int snp_issue_guest_request(u64 exit_code, struct snp_req_data *input, - unsigned long *fw_err) +static inline int snp_issue_guest_request(u64 exit_code, struct snp_req_data *input, struct snp_guest_request_ioctl *rio) { return -ENOTTY; } diff --git a/arch/x86/kernel/sev.c b/arch/x86/kernel/sev.c index 3f664ab277c4..b031244d6d2d 100644 --- a/arch/x86/kernel/sev.c +++ b/arch/x86/kernel/sev.c @@ -22,6 +22,8 @@ #include <linux/efi.h> #include <linux/platform_device.h> #include <linux/io.h> +#include <linux/psp-sev.h> +#include <uapi/linux/sev-guest.h> #include <asm/cpu_entry_area.h> #include <asm/stacktrace.h> @@ -2175,7 +2177,7 @@ static int __init init_sev_config(char *str) } __setup("sev=", init_sev_config); -int snp_issue_guest_request(u64 exit_code, struct snp_req_data *input, unsigned long *fw_err) +int snp_issue_guest_request(u64 exit_code, struct snp_req_data *input, struct snp_guest_request_ioctl *rio) { struct ghcb_state state; struct es_em_ctxt ctxt; @@ -2183,8 +2185,7 @@ int snp_issue_guest_request(u64 exit_code, struct snp_req_data *input, unsigned struct ghcb *ghcb; int ret; - if (!fw_err) - return -EINVAL; + rio->exitinfo2 = SEV_RET_NO_FW_CALL; /* * __sev_get_ghcb() needs to run with IRQs disabled because it is using @@ -2209,16 +2210,16 @@ int snp_issue_guest_request(u64 exit_code, struct snp_req_data *input, unsigned if (ret) goto e_put; - *fw_err = ghcb->save.sw_exit_info_2; - switch (*fw_err) { + rio->exitinfo2 = ghcb->save.sw_exit_info_2; + switch (rio->exitinfo2) { case 0: break; - case SNP_GUEST_REQ_ERR_BUSY: + case SNP_GUEST_VMM_ERR(SNP_GUEST_VMM_ERR_BUSY): ret = -EAGAIN; break; - case SNP_GUEST_REQ_INVALID_LEN: + case SNP_GUEST_VMM_ERR(SNP_GUEST_VMM_ERR_INVALID_LEN): /* Number of expected pages are returned in RBX */ if (exit_code == SVM_VMGEXIT_EXT_GUEST_REQUEST) { input->data_npages = ghcb_get_rbx(ghcb); |