From: Tianyu Lan <Tianyu.Lan@xxxxxxxxxxxxx> Hyper-V Isolation VM code uses sev_es_ghcb_hv_call() to read/write MSR via ghcb page. The SEV-ES guest should call the sev_es_negotiate_protocol() to negotiate the GHCB protocol version before establishing the GHCB. Call sev_es_negotiate_protocol() in the hyperv_init_ghcb(). Signed-off-by: Tianyu Lan <Tianyu.Lan@xxxxxxxxxxxxx> --- This patch based on the "Add AMD Secure Nested Paging (SEV-SNP) Guest Support" patchset. https://lore.kernel.org/lkml/20220128171804.569796-1-brijesh.singh@xxxxxxx/ arch/x86/hyperv/hv_init.c | 6 ++++++ arch/x86/include/asm/sev.h | 2 ++ arch/x86/kernel/sev-shared.c | 2 +- arch/x86/kernel/sev.c | 4 ++-- 4 files changed, 11 insertions(+), 3 deletions(-) diff --git a/arch/x86/hyperv/hv_init.c b/arch/x86/hyperv/hv_init.c index 24f4a06ac46a..a22303fccf02 100644 --- a/arch/x86/hyperv/hv_init.c +++ b/arch/x86/hyperv/hv_init.c @@ -28,6 +28,7 @@ #include <linux/syscore_ops.h> #include <clocksource/hyperv_timer.h> #include <linux/highmem.h> +#include <asm/sev.h> int hyperv_init_cpuhp; u64 hv_current_partition_id = ~0ull; @@ -69,6 +70,11 @@ static int hyperv_init_ghcb(void) ghcb_base = (void **)this_cpu_ptr(hv_ghcb_pg); *ghcb_base = ghcb_va; + sev_es_negotiate_protocol(); + + /* Write ghcb page back after negotiating protocol. */ + wrmsrl(MSR_AMD64_SEV_ES_GHCB, ghcb_gpa); + VMGEXIT(); return 0; } diff --git a/arch/x86/include/asm/sev.h b/arch/x86/include/asm/sev.h index 7a5934af9d47..fc6b0c526492 100644 --- a/arch/x86/include/asm/sev.h +++ b/arch/x86/include/asm/sev.h @@ -120,6 +120,8 @@ extern enum es_result sev_es_ghcb_hv_call(struct ghcb *ghcb, struct es_em_ctxt *ctxt, u64 exit_code, u64 exit_info_1, u64 exit_info_2); +extern bool sev_es_negotiate_protocol(void); + static inline int rmpadjust(unsigned long vaddr, bool rmp_psize, unsigned long attrs) { int rc; diff --git a/arch/x86/kernel/sev-shared.c b/arch/x86/kernel/sev-shared.c index ce06cb7c8ed0..8b8af5a8d402 100644 --- a/arch/x86/kernel/sev-shared.c +++ b/arch/x86/kernel/sev-shared.c @@ -145,7 +145,7 @@ static void snp_register_ghcb_early(unsigned long paddr) sev_es_terminate(SEV_TERM_SET_LINUX, GHCB_TERM_REGISTER); } -static bool sev_es_negotiate_protocol(void) +bool sev_es_negotiate_protocol(void) { u64 val; diff --git a/arch/x86/kernel/sev.c b/arch/x86/kernel/sev.c index 3568b3303314..46c53c4885ee 100644 --- a/arch/x86/kernel/sev.c +++ b/arch/x86/kernel/sev.c @@ -167,12 +167,12 @@ void noinstr __sev_es_ist_exit(void) this_cpu_write(cpu_tss_rw.x86_tss.ist[IST_INDEX_VC], *(unsigned long *)ist); } -static inline u64 sev_es_rd_ghcb_msr(void) +inline u64 sev_es_rd_ghcb_msr(void) { return __rdmsr(MSR_AMD64_SEV_ES_GHCB); } -static __always_inline void sev_es_wr_ghcb_msr(u64 val) +__always_inline void sev_es_wr_ghcb_msr(u64 val) { u32 low, high; -- 2.25.1
