The AMD FRED (Flexible Return and Event Delivery) feature introduces several new fields to the VMCB save area. These fields include FRED-specific stack pointers (fred_rsp[1-3], fred_ssp[1-3]), stack level tracking (fred_stklvls), and configuration (fred_config), and the control-area fields exit_int_data and event_inj_data. Note that fred_rsp0 is only saved/restored for SEV-ES guests. All FRED MSRs are zeroed on RESET. Reproduce the HW behavior here to ensure that vCPU starts with a valid FRED state. Also update the size of save areas of VMCB. Co-developed-by: Neeraj Upadhyay Signed-off-by: Neeraj Upadhyay Signed-off-by: Shivansh Dhiman Reviewed-by: Nikunj A Dadhania --- Changes in v3: * Update the fields and offsets of FRED MSRs according to the latest APM. * Dropped fred_rsp0 from vmcb_save_area. Hardware doesn't save/restore it for non-SEV-ES guests. Move its handling to patch 3. * Updated the commit message. Changes in v2: * Modified the zeroing of FRED MSRs from INIT to RESET and updated the commit message (Sean Christopherson). --- arch/x86/include/asm/svm.h | 31 ++++++++++++++++++++++++++++--- arch/x86/kvm/svm/svm.c | 11 +++++++++++ 2 files changed, 39 insertions(+), 3 deletions(-) diff --git a/arch/x86/include/asm/svm.h b/arch/x86/include/asm/svm.h index aa63431ba92c..0570581e251a 100644 --- a/arch/x86/include/asm/svm.h +++ b/arch/x86/include/asm/svm.h @@ -165,7 +165,10 @@ struct __attribute__ ((__packed__)) vmcb_control_area { u8 reserved_9[22]; u64 allowed_sev_features; /* Offset 0x138 */ u64 guest_sev_features; /* Offset 0x140 */ - u8 reserved_10[664]; + u8 reserved_10[40]; + u64 exit_int_data; /* Offset 0x170 */ + u64 event_inj_data; + u8 reserved_11[608]; /* * Offset 0x3e0, 32 bytes reserved * for use by hypervisor/software. @@ -370,6 +373,15 @@ struct vmcb_save_area { u64 last_excp_to; u8 reserved_0x298[72]; u64 spec_ctrl; /* Guest version of SPEC_CTRL at 0x2E0 */ + u8 reserved_0x2e8[1496]; + u64 fred_rsp1; + u64 fred_rsp2; + u64 fred_rsp3; + u64 fred_stklvls; + u64 fred_ssp1; + u64 fred_ssp2; + u64 fred_ssp3; + u64 fred_config; } __packed; /* Save area definition for SEV-ES and SEV-SNP guests */ @@ -482,6 +494,18 @@ struct sev_es_save_area { u8 fpreg_x87[80]; u8 fpreg_xmm[256]; u8 fpreg_ymm[256]; + u8 reserved_0x670[568]; + u64 guest_exit_int_data; + u64 guest_event_inj_data; + u64 fred_rsp0; + u64 fred_rsp1; + u64 fred_rsp2; + u64 fred_rsp3; + u64 fred_stklvls; + u64 fred_ssp1; + u64 fred_ssp2; + u64 fred_ssp3; + u64 fred_config; } __packed; struct ghcb_save_area { @@ -552,9 +576,9 @@ struct vmcb { }; } __packed; -#define EXPECTED_VMCB_SAVE_AREA_SIZE 744 +#define EXPECTED_VMCB_SAVE_AREA_SIZE 2304 #define EXPECTED_GHCB_SAVE_AREA_SIZE 1032 -#define EXPECTED_SEV_ES_SAVE_AREA_SIZE 1648 +#define EXPECTED_SEV_ES_SAVE_AREA_SIZE 2304 #define EXPECTED_VMCB_CONTROL_AREA_SIZE 1024 #define EXPECTED_GHCB_SIZE PAGE_SIZE @@ -578,6 +602,7 @@ static inline void __unused_size_checks(void) BUILD_BUG_RESERVED_OFFSET(vmcb_save_area, 0x180); BUILD_BUG_RESERVED_OFFSET(vmcb_save_area, 0x248); BUILD_BUG_RESERVED_OFFSET(vmcb_save_area, 0x298); + BUILD_BUG_RESERVED_OFFSET(vmcb_save_area, 0x2e8); BUILD_BUG_RESERVED_OFFSET(sev_es_save_area, 0xc8); BUILD_BUG_RESERVED_OFFSET(sev_es_save_area, 0xcc); diff --git a/arch/x86/kvm/svm/svm.c b/arch/x86/kvm/svm/svm.c index dd19c7b4e904..6d55b0a576d9 100644 --- a/arch/x86/kvm/svm/svm.c +++ b/arch/x86/kvm/svm/svm.c @@ -1217,6 +1217,17 @@ static void init_vmcb(struct kvm_vcpu *vcpu, bool init_event) save->idtr.base = 0; save->idtr.limit = 0xffff; + if (!init_event) { + save->fred_rsp1 = 0; + save->fred_rsp2 = 0; + save->fred_rsp3 = 0; + save->fred_stklvls = 0; + save->fred_ssp1 = 0; + save->fred_ssp2 = 0; + save->fred_ssp3 = 0; + save->fred_config = 0; + } + init_sys_seg(&save->ldtr, SEG_TYPE_LDT); init_sys_seg(&save->tr, SEG_TYPE_BUSY_TSS16); -- 2.43.0