[PATCH v2 4/7] KVM: SVM: hyper-v: Nested enlightenments in VMCB

[Vineeth Pillai <viremana@linux.microsoft.com>]

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@linux.microsoft.com>
---
 arch/x86/include/asm/svm.h | 24 +++++++++++++++++++++++-
 arch/x86/kvm/svm/svm.c     |  8 ++++++++
 arch/x86/kvm/svm/svm.h     | 30 ++++++++++++++++++++++++++++--
 3 files changed, 59 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.c b/arch/x86/kvm/svm/svm.c
index baee91c1e936..2ad1f55c88d0 100644
--- a/arch/x86/kvm/svm/svm.c
+++ b/arch/x86/kvm/svm/svm.c
@@ -31,6 +31,7 @@
 #include <asm/tlbflush.h>
 #include <asm/desc.h>
 #include <asm/debugreg.h>
+#include <asm/hypervisor.h>
 #include <asm/kvm_para.h>
 #include <asm/irq_remapping.h>
 #include <asm/spec-ctrl.h>
@@ -122,6 +123,8 @@ bool npt_enabled = true;
 bool npt_enabled;
 #endif
 
+u32 __read_mostly vmcb_all_clean_mask = VMCB_ALL_CLEAN_MASK;
+
 /*
  * These 2 parameters are used to config the controls for Pause-Loop Exiting:
  * pause_filter_count: On processors that support Pause filtering(indicated
@@ -1051,6 +1054,11 @@ static __init int svm_hardware_setup(void)
 	 */
 	allow_smaller_maxphyaddr = !npt_enabled;
 
+#if IS_ENABLED(CONFIG_HYPERV)
+	if (hypervisor_is_type(X86_HYPER_MS_HYPERV))
+		vmcb_all_clean_mask |= VMCB_HYPERV_CLEAN_MASK;
+#endif
+
 	return 0;
 
 err:
diff --git a/arch/x86/kvm/svm/svm.h b/arch/x86/kvm/svm/svm.h
index 39e071fdab0c..63ed05c8027b 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 and VMCB_HYPERV_CLEAN_MASK might
+ * also need to be updated if this enum is modified.
+ */
 enum {
 	VMCB_INTERCEPTS, /* Intercept vectors, TSC offset,
 			    pause filter count */
@@ -50,12 +55,28 @@ enum {
 			  * AVIC PHYSICAL_TABLE pointer,
 			  * AVIC LOGICAL_TABLE pointer
 			  */
-	VMCB_DIRTY_MAX,
+#if IS_ENABLED(CONFIG_HYPERV)
+	VMCB_HV_NESTED_ENLIGHTENMENTS = 31,
+#endif
 };
 
+#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)			\
+	)
+
+#if IS_ENABLED(CONFIG_HYPERV)
+#define VMCB_HYPERV_CLEAN_MASK (1U << VMCB_HV_NESTED_ENLIGHTENMENTS)
+#endif
+
 /* TPR and CR2 are always written before VMRUN */
 #define VMCB_ALWAYS_DIRTY_MASK	((1U << VMCB_INTR) | (1U << VMCB_CR2))
 
+extern u32 vmcb_all_clean_mask __read_mostly;
+
 struct kvm_sev_info {
 	bool active;		/* SEV enabled guest */
 	bool es_active;		/* SEV-ES enabled guest */
@@ -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