KVM: SVM: Create a separate mapping for the SEV-ES save area

The save area for SEV-ES/SEV-SNP guests, as used by the hardware, is
different from the save area of a non SEV-ES/SEV-SNP guest.

This is the first step in defining the multiple save areas to keep them
separate and ensuring proper operation amongst the different types of
guests. Create an SEV-ES/SEV-SNP save area and adjust usage to the new
save area definition where needed.

Signed-off-by: Tom Lendacky <thomas.lendacky@amd.com>
Signed-off-by: Brijesh Singh <brijesh.singh@amd.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Venu Busireddy <venu.busireddy@oracle.com>
Link: https://lore.kernel.org/r/20220405182743.308853-1-brijesh.singh@amd.com

diff --git a/arch/x86/include/asm/svm.h b/arch/x86/include/asm/svm.h
index f2d01f351e953edd0eb66dbdb7e08eb05ea22a12..788a43f990809c84c15eb28872ad581185cebeea 100644 (file)
--- a/arch/x86/include/asm/svm.h
+++ b/arch/x86/include/asm/svm.h
@@ -271,6 +271,7 @@ struct vmcb_seg {
        u64 base;
 } __packed;
 
+/* Save area definition for legacy and SEV-MEM guests */
 struct vmcb_save_area {
        struct vmcb_seg es;
        struct vmcb_seg cs;
@@ -287,8 +288,58 @@ struct vmcb_save_area {
        u8 cpl;
        u8 reserved_2[4];
        u64 efer;
+       u8 reserved_3[112];
+       u64 cr4;
+       u64 cr3;
+       u64 cr0;
+       u64 dr7;
+       u64 dr6;
+       u64 rflags;
+       u64 rip;
+       u8 reserved_4[88];
+       u64 rsp;
+       u64 s_cet;
+       u64 ssp;
+       u64 isst_addr;
+       u64 rax;
+       u64 star;
+       u64 lstar;
+       u64 cstar;
+       u64 sfmask;
+       u64 kernel_gs_base;
+       u64 sysenter_cs;
+       u64 sysenter_esp;
+       u64 sysenter_eip;
+       u64 cr2;
+       u8 reserved_5[32];
+       u64 g_pat;
+       u64 dbgctl;
+       u64 br_from;
+       u64 br_to;
+       u64 last_excp_from;
+       u64 last_excp_to;
+       u8 reserved_6[72];
+       u32 spec_ctrl;          /* Guest version of SPEC_CTRL at 0x2E0 */
+} __packed;
+
+/* Save area definition for SEV-ES and SEV-SNP guests */
+struct sev_es_save_area {
+       struct vmcb_seg es;
+       struct vmcb_seg cs;
+       struct vmcb_seg ss;
+       struct vmcb_seg ds;
+       struct vmcb_seg fs;
+       struct vmcb_seg gs;
+       struct vmcb_seg gdtr;
+       struct vmcb_seg ldtr;
+       struct vmcb_seg idtr;
+       struct vmcb_seg tr;
+       u8 reserved_1[43];
+       u8 cpl;
+       u8 reserved_2[4];
+       u64 efer;
        u8 reserved_3[104];
-       u64 xss;                /* Valid for SEV-ES only */
+       u64 xss;
        u64 cr4;
        u64 cr3;
        u64 cr0;
@@ -316,22 +367,14 @@ struct vmcb_save_area {
        u64 br_to;
        u64 last_excp_from;
        u64 last_excp_to;
-
-       /*
-        * The following part of the save area is valid only for
-        * SEV-ES guests when referenced through the GHCB or for
-        * saving to the host save area.
-        */
-       u8 reserved_7[72];
-       u32 spec_ctrl;          /* Guest version of SPEC_CTRL at 0x2E0 */
-       u8 reserved_7b[4];
+       u8 reserved_7[80];
        u32 pkru;
-       u8 reserved_7a[20];
-       u64 reserved_8;         /* rax already available at 0x01f8 */
+       u8 reserved_9[20];
+       u64 reserved_10;        /* rax already available at 0x01f8 */
        u64 rcx;
        u64 rdx;
        u64 rbx;
-       u64 reserved_9;         /* rsp already available at 0x01d8 */
+       u64 reserved_11;        /* rsp already available at 0x01d8 */
        u64 rbp;
        u64 rsi;
        u64 rdi;
@@ -343,23 +386,25 @@ struct vmcb_save_area {
        u64 r13;
        u64 r14;
        u64 r15;
-       u8 reserved_10[16];
+       u8 reserved_12[16];
        u64 sw_exit_code;
        u64 sw_exit_info_1;
        u64 sw_exit_info_2;
        u64 sw_scratch;
        u64 sev_features;
-       u8 reserved_11[48];
+       u8 reserved_13[48];
        u64 xcr0;
        u8 valid_bitmap[16];
        u64 x87_state_gpa;
 } __packed;
 
+#define GHCB_SHARED_BUF_SIZE   2032
+
 struct ghcb {
-       struct vmcb_save_area save;
-       u8 reserved_save[2048 - sizeof(struct vmcb_save_area)];
+       struct sev_es_save_area save;
+       u8 reserved_save[2048 - sizeof(struct sev_es_save_area)];
 
-       u8 shared_buffer[2032];
+       u8 shared_buffer[GHCB_SHARED_BUF_SIZE];
 
        u8 reserved_1[10];
        u16 protocol_version;   /* negotiated SEV-ES/GHCB protocol version */
@@ -367,13 +412,15 @@ struct ghcb {
 } __packed;
 
 
-#define EXPECTED_VMCB_SAVE_AREA_SIZE           1032
+#define EXPECTED_VMCB_SAVE_AREA_SIZE           740
+#define EXPECTED_SEV_ES_SAVE_AREA_SIZE         1032
 #define EXPECTED_VMCB_CONTROL_AREA_SIZE                1024
 #define EXPECTED_GHCB_SIZE                     PAGE_SIZE
 
 static inline void __unused_size_checks(void)
 {
        BUILD_BUG_ON(sizeof(struct vmcb_save_area)      != EXPECTED_VMCB_SAVE_AREA_SIZE);
+       BUILD_BUG_ON(sizeof(struct sev_es_save_area)    != EXPECTED_SEV_ES_SAVE_AREA_SIZE);
        BUILD_BUG_ON(sizeof(struct vmcb_control_area)   != EXPECTED_VMCB_CONTROL_AREA_SIZE);
        BUILD_BUG_ON(sizeof(struct ghcb)                != EXPECTED_GHCB_SIZE);
 }
@@ -443,7 +490,7 @@ struct vmcb {
 /* GHCB Accessor functions */
 
 #define GHCB_BITMAP_IDX(field)                                                 \
-       (offsetof(struct vmcb_save_area, field) / sizeof(u64))
+       (offsetof(struct sev_es_save_area, field) / sizeof(u64))
 
 #define DEFINE_GHCB_ACCESSORS(field)                                           \
        static inline bool ghcb_##field##_is_valid(const struct ghcb *ghcb)     \

diff --git a/arch/x86/kvm/svm/sev.c b/arch/x86/kvm/svm/sev.c
index 75fa6dd268f056644446ef5db4c596658d08097b..6e18ec1839f0a9eb222be8e601af7d7984ffbc09 100644 (file)
--- a/arch/x86/kvm/svm/sev.c
+++ b/arch/x86/kvm/svm/sev.c
@@ -559,12 +559,20 @@ e_unpin:
 
 static int sev_es_sync_vmsa(struct vcpu_svm *svm)
 {
-       struct vmcb_save_area *save = &svm->vmcb->save;
+       struct sev_es_save_area *save = svm->sev_es.vmsa;
 
        /* Check some debug related fields before encrypting the VMSA */
-       if (svm->vcpu.guest_debug || (save->dr7 & ~DR7_FIXED_1))
+       if (svm->vcpu.guest_debug || (svm->vmcb->save.dr7 & ~DR7_FIXED_1))
                return -EINVAL;
 
+       /*
+        * SEV-ES will use a VMSA that is pointed to by the VMCB, not
+        * the traditional VMSA that is part of the VMCB. Copy the
+        * traditional VMSA as it has been built so far (in prep
+        * for LAUNCH_UPDATE_VMSA) to be the initial SEV-ES state.
+        */
+       memcpy(save, &svm->vmcb->save, sizeof(svm->vmcb->save));
+
        /* Sync registgers */
        save->rax = svm->vcpu.arch.regs[VCPU_REGS_RAX];
        save->rbx = svm->vcpu.arch.regs[VCPU_REGS_RBX];
@@ -592,14 +600,6 @@ static int sev_es_sync_vmsa(struct vcpu_svm *svm)
        save->xss  = svm->vcpu.arch.ia32_xss;
        save->dr6  = svm->vcpu.arch.dr6;
 
-       /*
-        * SEV-ES will use a VMSA that is pointed to by the VMCB, not
-        * the traditional VMSA that is part of the VMCB. Copy the
-        * traditional VMSA as it has been built so far (in prep
-        * for LAUNCH_UPDATE_VMSA) to be the initial SEV-ES state.
-        */
-       memcpy(svm->sev_es.vmsa, save, sizeof(*save));
-
        return 0;
 }
 
@@ -2932,7 +2932,7 @@ void sev_es_vcpu_reset(struct vcpu_svm *svm)
                                            sev_enc_bit));
 }
 
-void sev_es_prepare_switch_to_guest(struct vmcb_save_area *hostsa)
+void sev_es_prepare_switch_to_guest(struct sev_es_save_area *hostsa)
 {
        /*
         * As an SEV-ES guest, hardware will restore the host state on VMEXIT,

diff --git a/arch/x86/kvm/svm/svm.c b/arch/x86/kvm/svm/svm.c
index 81cb518170a8e8d4dc915744b5b6d882569d7e04..6ff595f74e3ab5e736e6f997ebf1b978c9021607 100644 (file)
--- a/arch/x86/kvm/svm/svm.c
+++ b/arch/x86/kvm/svm/svm.c
@@ -1270,8 +1270,8 @@ static void svm_prepare_switch_to_guest(struct kvm_vcpu *vcpu)
         */
        vmsave(__sme_page_pa(sd->save_area));
        if (sev_es_guest(vcpu->kvm)) {
-               struct vmcb_save_area *hostsa;
-               hostsa = (struct vmcb_save_area *)(page_address(sd->save_area) + 0x400);
+               struct sev_es_save_area *hostsa;
+               hostsa = (struct sev_es_save_area *)(page_address(sd->save_area) + 0x400);
 
                sev_es_prepare_switch_to_guest(hostsa);
        }

diff --git a/arch/x86/kvm/svm/svm.h b/arch/x86/kvm/svm/svm.h
index f77a7d2d39dd6dfe30b94b5cca2665435f378a00..cc857deaee5e7d85b0889594693e29d5b287b42c 100644 (file)
--- a/arch/x86/kvm/svm/svm.h
+++ b/arch/x86/kvm/svm/svm.h
@@ -181,7 +181,7 @@ struct svm_nested_state {
 
 struct vcpu_sev_es_state {
        /* SEV-ES support */
-       struct vmcb_save_area *vmsa;
+       struct sev_es_save_area *vmsa;
        struct ghcb *ghcb;
        struct kvm_host_map ghcb_map;
        bool received_first_sipi;
@@ -620,7 +620,7 @@ int sev_es_string_io(struct vcpu_svm *svm, int size, unsigned int port, int in);
 void sev_es_init_vmcb(struct vcpu_svm *svm);
 void sev_es_vcpu_reset(struct vcpu_svm *svm);
 void sev_vcpu_deliver_sipi_vector(struct kvm_vcpu *vcpu, u8 vector);
-void sev_es_prepare_switch_to_guest(struct vmcb_save_area *hostsa);
+void sev_es_prepare_switch_to_guest(struct sev_es_save_area *hostsa);
 void sev_es_unmap_ghcb(struct vcpu_svm *svm);
 
 /* vmenter.S */