[PATCH 4/7] KVM: SVM: hyper-v: Nested enlightenments in VMCB

From: Vineeth Pillai
Date: Wed Apr 07 2021 - 10:42:11 EST


Add Hyper-V specific fields in VMCB to support SVM enlightenments.
Also a small refactoring of VMCB clean bits handling.

Signed-off-by: Vineeth Pillai <viremana@xxxxxxxxxxxxxxxxxxx>
---
arch/x86/include/asm/svm.h | 24 +++++++++++++++++++++++-
arch/x86/kvm/svm/svm.h | 30 ++++++++++++++++++++++++++++--
2 files changed, 51 insertions(+), 3 deletions(-)

diff --git a/arch/x86/include/asm/svm.h b/arch/x86/include/asm/svm.h
index 1c561945b426..3586d7523ce8 100644
--- a/arch/x86/include/asm/svm.h
+++ b/arch/x86/include/asm/svm.h
@@ -322,9 +322,31 @@ static inline void __unused_size_checks(void)
BUILD_BUG_ON(sizeof(struct ghcb) != EXPECTED_GHCB_SIZE);
}

+
+#if IS_ENABLED(CONFIG_HYPERV)
+struct __packed hv_enlightenments {
+ struct __packed hv_enlightenments_control {
+ u32 nested_flush_hypercall:1;
+ u32 msr_bitmap:1;
+ u32 enlightened_npt_tlb: 1;
+ u32 reserved:29;
+ } hv_enlightenments_control;
+ u32 hv_vp_id;
+ u64 hv_vm_id;
+ u64 partition_assist_page;
+ u64 reserved;
+};
+#define VMCB_CONTROL_END 992 // 32 bytes for Hyper-V
+#else
+#define VMCB_CONTROL_END 1024
+#endif
+
struct vmcb {
struct vmcb_control_area control;
- u8 reserved_control[1024 - sizeof(struct vmcb_control_area)];
+ u8 reserved_control[VMCB_CONTROL_END - sizeof(struct vmcb_control_area)];
+#if IS_ENABLED(CONFIG_HYPERV)
+ struct hv_enlightenments hv_enlightenments;
+#endif
struct vmcb_save_area save;
} __packed;

diff --git a/arch/x86/kvm/svm/svm.h b/arch/x86/kvm/svm/svm.h
index 39e071fdab0c..842c8764a68c 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.
+ * Should update VMCB_ALL_CLEAN_MASK also
+ * if this enum is modified.
+ */
enum {
VMCB_INTERCEPTS, /* Intercept vectors, TSC offset,
pause filter count */
@@ -50,9 +55,25 @@ enum {
* AVIC PHYSICAL_TABLE pointer,
* AVIC LOGICAL_TABLE pointer
*/
- VMCB_DIRTY_MAX,
+#if IS_ENABLED(CONFIG_HYPERV)
+ VMCB_HV_NESTED_ENLIGHTENMENTS = 31,
+#endif
};

+#define __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) \
+ )
+
+#if IS_ENABLED(CONFIG_HYPERV)
+#define VMCB_ALL_CLEAN_MASK (__CLEAN_MASK | (1U << VMCB_HV_NESTED_ENLIGHTENMENTS))
+#else
+#define VMCB_ALL_CLEAN_MASK __CLEAN_MASK
+#endif
+
/* TPR and CR2 are always written before VMRUN */
#define VMCB_ALWAYS_DIRTY_MASK ((1U << VMCB_INTR) | (1U << VMCB_CR2))

@@ -230,7 +251,7 @@ 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;
}

@@ -239,6 +260,11 @@ static inline void vmcb_mark_dirty(struct vmcb *vmcb, int bit)
vmcb->control.clean &= ~(1 << bit);
}

+static inline bool vmcb_is_clean(struct vmcb *vmcb, int bit)
+{
+ return (vmcb->control.clean & (1 << bit));
+}
+
static inline struct vcpu_svm *to_svm(struct kvm_vcpu *vcpu)
{
return container_of(vcpu, struct vcpu_svm, vcpu);
--
2.25.1