[PATCH v4 4/7] KVM: SVM: Software reserved fields
From: Vineeth Pillai <hidden>
Date: 2021-04-27 20:55:23
Also in:
kvm, lkml
Subsystem:
kernel virtual machine for x86 (kvm/x86), the rest, x86 architecture (32-bit and 64-bit) · Maintainers:
Sean Christopherson, Paolo Bonzini, Linus Torvalds, Thomas Gleixner, Ingo Molnar, Borislav Petkov, Dave Hansen
SVM added support for certain reserved fields to be used by software or hypervisor. Add the following reserved fields: - VMCB offset 0x3e0 - 0x3ff - Clean bit 31 - SVM intercept exit code 0xf0000000 Later patches will make use of this for supporting Hyper-V nested virtualization enhancements. Signed-off-by: Vineeth Pillai <redacted> --- arch/x86/include/asm/svm.h | 9 +++++++-- arch/x86/include/uapi/asm/svm.h | 3 +++ arch/x86/kvm/svm/svm.h | 17 +++++++++++++++-- 3 files changed, 25 insertions(+), 4 deletions(-)
diff --git a/arch/x86/include/asm/svm.h b/arch/x86/include/asm/svm.h
index 1c561945b426..8dac318bd6f9 100644
--- a/arch/x86/include/asm/svm.h
+++ b/arch/x86/include/asm/svm.h@@ -156,6 +156,12 @@ struct __attribute__ ((__packed__)) vmcb_control_area { u64 avic_physical_id; /* Offset 0xf8 */ u8 reserved_7[8]; u64 vmsa_pa; /* Used for an SEV-ES guest */ + u8 reserved_8[720]; + /* + * Offset 0x3e0, 32 bytes reserved + * for use by hypervisor/software. + */ + u8 reserved_sw[32]; };
@@ -312,7 +318,7 @@ struct ghcb { #define EXPECTED_VMCB_SAVE_AREA_SIZE 1032 -#define EXPECTED_VMCB_CONTROL_AREA_SIZE 272 +#define EXPECTED_VMCB_CONTROL_AREA_SIZE 1024 #define EXPECTED_GHCB_SIZE PAGE_SIZE static inline void __unused_size_checks(void)
@@ -324,7 +330,6 @@ static inline void __unused_size_checks(void) struct vmcb { struct vmcb_control_area control; - u8 reserved_control[1024 - sizeof(struct vmcb_control_area)]; struct vmcb_save_area save; } __packed;
diff --git a/arch/x86/include/uapi/asm/svm.h b/arch/x86/include/uapi/asm/svm.h
index 554f75fe013c..efa969325ede 100644
--- a/arch/x86/include/uapi/asm/svm.h
+++ b/arch/x86/include/uapi/asm/svm.h@@ -110,6 +110,9 @@ #define SVM_VMGEXIT_GET_AP_JUMP_TABLE 1 #define SVM_VMGEXIT_UNSUPPORTED_EVENT 0x8000ffff +/* Exit code reserved for hypervisor/software use */ +#define SVM_EXIT_SW 0xf0000000 + #define SVM_EXIT_ERR -1 #define SVM_EXIT_REASONS \
diff --git a/arch/x86/kvm/svm/svm.h b/arch/x86/kvm/svm/svm.h
index 39e071fdab0c..4e073b88c8cb 100644
--- a/arch/x86/kvm/svm/svm.h
+++ b/arch/x86/kvm/svm/svm.h@@ -33,6 +33,11 @@ static const u32 host_save_user_msrs[] = { extern u32 msrpm_offsets[MSRPM_OFFSETS] __read_mostly; extern bool npt_enabled; +/* + * Clean bits in VMCB. + * VMCB_ALL_CLEAN_MASK might also need to + * be updated if this enum is modified. + */ enum { VMCB_INTERCEPTS, /* Intercept vectors, TSC offset, pause filter count */
@@ -50,9 +55,17 @@ enum { * AVIC PHYSICAL_TABLE pointer, * AVIC LOGICAL_TABLE pointer */ - VMCB_DIRTY_MAX, + VMCB_SW = 31, /* Reserved for hypervisor/software use */ }; +#define VMCB_ALL_CLEAN_MASK ( \ + (1U << VMCB_INTERCEPTS) | (1U << VMCB_PERM_MAP) | \ + (1U << VMCB_ASID) | (1U << VMCB_INTR) | \ + (1U << VMCB_NPT) | (1U << VMCB_CR) | (1U << VMCB_DR) | \ + (1U << VMCB_DT) | (1U << VMCB_SEG) | (1U << VMCB_CR2) | \ + (1U << VMCB_LBR) | (1U << VMCB_AVIC) | \ + (1U << VMCB_SW)) + /* TPR and CR2 are always written before VMRUN */ #define VMCB_ALWAYS_DIRTY_MASK ((1U << VMCB_INTR) | (1U << VMCB_CR2))
@@ -230,7 +243,7 @@ static inline void vmcb_mark_all_dirty(struct vmcb *vmcb) static inline void vmcb_mark_all_clean(struct vmcb *vmcb) { - vmcb->control.clean = ((1 << VMCB_DIRTY_MAX) - 1) + vmcb->control.clean = VMCB_ALL_CLEAN_MASK & ~VMCB_ALWAYS_DIRTY_MASK; }
--
2.25.1