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| author | Tom Lendacky <thomas.lendacky@amd.com> | 2024-06-05 10:18:46 -0500 |
|---|---|---|
| committer | Borislav Petkov (AMD) <bp@alien8.de> | 2024-06-11 07:22:46 +0200 |
| commit | 34ff659017359116dd58b1e008d99d21b96b3569 (patch) | |
| tree | e091392d2f03240e0efdee9c22b6a2dec884a5e7 /arch/x86/include/asm/sev.h | |
| parent | 878e70dbd26e234e6e6941dac3a233af6f632184 (diff) | |
| download | lwn-34ff659017359116dd58b1e008d99d21b96b3569.tar.gz lwn-34ff659017359116dd58b1e008d99d21b96b3569.zip | |
x86/sev: Use kernel provided SVSM Calling Areas
The SVSM Calling Area (CA) is used to communicate between Linux and the
SVSM. Since the firmware supplied CA for the BSP is likely to be in
reserved memory, switch off that CA to a kernel provided CA so that access
and use of the CA is available during boot. The CA switch is done using
the SVSM core protocol SVSM_CORE_REMAP_CA call.
An SVSM call is executed by filling out the SVSM CA and setting the proper
register state as documented by the SVSM protocol. The SVSM is invoked by
by requesting the hypervisor to run VMPL0.
Once it is safe to allocate/reserve memory, allocate a CA for each CPU.
After allocating the new CAs, the BSP will switch from the boot CA to the
per-CPU CA. The CA for an AP is identified to the SVSM when creating the
VMSA in preparation for booting the AP.
[ bp: Heavily simplify svsm_issue_call() asm, other touchups. ]
Signed-off-by: Tom Lendacky <thomas.lendacky@amd.com>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Link: https://lore.kernel.org/r/fa8021130bcc3bcf14d722a25548cb0cdf325456.1717600736.git.thomas.lendacky@amd.com
Diffstat (limited to 'arch/x86/include/asm/sev.h')
| -rw-r--r-- | arch/x86/include/asm/sev.h | 32 |
1 files changed, 32 insertions, 0 deletions
diff --git a/arch/x86/include/asm/sev.h b/arch/x86/include/asm/sev.h index 2a44376f9f91..4145928d2874 100644 --- a/arch/x86/include/asm/sev.h +++ b/arch/x86/include/asm/sev.h @@ -178,6 +178,36 @@ struct svsm_ca { u8 svsm_buffer[PAGE_SIZE - 8]; }; +#define SVSM_SUCCESS 0 +#define SVSM_ERR_INCOMPLETE 0x80000000 +#define SVSM_ERR_UNSUPPORTED_PROTOCOL 0x80000001 +#define SVSM_ERR_UNSUPPORTED_CALL 0x80000002 +#define SVSM_ERR_INVALID_ADDRESS 0x80000003 +#define SVSM_ERR_INVALID_FORMAT 0x80000004 +#define SVSM_ERR_INVALID_PARAMETER 0x80000005 +#define SVSM_ERR_INVALID_REQUEST 0x80000006 +#define SVSM_ERR_BUSY 0x80000007 + +/* + * SVSM protocol structure + */ +struct svsm_call { + struct svsm_ca *caa; + u64 rax; + u64 rcx; + u64 rdx; + u64 r8; + u64 r9; + u64 rax_out; + u64 rcx_out; + u64 rdx_out; + u64 r8_out; + u64 r9_out; +}; + +#define SVSM_CORE_CALL(x) ((0ULL << 32) | (x)) +#define SVSM_CORE_REMAP_CA 0 + #ifdef CONFIG_AMD_MEM_ENCRYPT extern void __sev_es_ist_enter(struct pt_regs *regs); extern void __sev_es_ist_exit(void); @@ -260,6 +290,7 @@ void snp_accept_memory(phys_addr_t start, phys_addr_t end); u64 snp_get_unsupported_features(u64 status); u64 sev_get_status(void); void sev_show_status(void); +void snp_update_svsm_ca(void); #else static inline void sev_es_ist_enter(struct pt_regs *regs) { } static inline void sev_es_ist_exit(void) { } @@ -289,6 +320,7 @@ static inline void snp_accept_memory(phys_addr_t start, phys_addr_t end) { } static inline u64 snp_get_unsupported_features(u64 status) { return 0; } static inline u64 sev_get_status(void) { return 0; } static inline void sev_show_status(void) { } +static inline void snp_update_svsm_ca(void) { } #endif #ifdef CONFIG_KVM_AMD_SEV |