[PATCH 12/15] KVM: x86: Track possible passthrough MSRs in kvm_x86_ops

[Aaron Lewis <aaronlewis@google.com>]

Move the possible passthrough MSRs to kvm_x86_ops.  Doing this allows
them to be accessed from common x86 code.

In order to set the passthrough MSRs in kvm_x86_ops for VMX,
"vmx_possible_passthrough_msrs" had to be relocated to main.c, and with
that vmx_msr_filter_changed() had to be moved too because it uses
"vmx_possible_passthrough_msrs".

Signed-off-by: Sean Christopherson <seanjc@google.com>
Co-developed-by: Aaron Lewis <aaronlewis@google.com>
---
 arch/x86/include/asm/kvm_host.h |  3 ++
 arch/x86/kvm/svm/svm.c          | 18 ++-------
 arch/x86/kvm/vmx/main.c         | 58 ++++++++++++++++++++++++++++
 arch/x86/kvm/vmx/vmx.c          | 67 ++-------------------------------
 arch/x86/kvm/x86.c              | 13 +++++++
 arch/x86/kvm/x86.h              |  1 +
 6 files changed, 83 insertions(+), 77 deletions(-)

diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h
index 3e8afc82ae2fb..7e9fee4d36cc2 100644
--- a/arch/x86/include/asm/kvm_host.h
+++ b/arch/x86/include/asm/kvm_host.h
@@ -1817,6 +1817,9 @@ struct kvm_x86_ops {
 	int (*enable_l2_tlb_flush)(struct kvm_vcpu *vcpu);
 
 	void (*migrate_timers)(struct kvm_vcpu *vcpu);
+
+	const u32 * const possible_passthrough_msrs;
+	const u32 nr_possible_passthrough_msrs;
 	void (*msr_filter_changed)(struct kvm_vcpu *vcpu);
 	int (*complete_emulated_msr)(struct kvm_vcpu *vcpu, int err);
 
diff --git a/arch/x86/kvm/svm/svm.c b/arch/x86/kvm/svm/svm.c
index 4e30efe90c541..23e6515bb7904 100644
--- a/arch/x86/kvm/svm/svm.c
+++ b/arch/x86/kvm/svm/svm.c
@@ -755,18 +755,6 @@ static void clr_dr_intercepts(struct vcpu_svm *svm)
 	recalc_intercepts(svm);
 }
 
-static int direct_access_msr_slot(u32 msr)
-{
-	u32 i;
-
-	for (i = 0; i < ARRAY_SIZE(direct_access_msrs); i++) {
-		if (direct_access_msrs[i] == msr)
-			return i;
-	}
-
-	return -ENOENT;
-}
-
 static bool msr_write_intercepted(struct kvm_vcpu *vcpu, u32 msr)
 {
 	u8 bit_write;
@@ -832,7 +820,7 @@ void svm_disable_intercept_for_msr(struct kvm_vcpu *vcpu, u32 msr, int type)
 	struct vcpu_svm *svm = to_svm(vcpu);
 	int slot;
 
-	slot = direct_access_msr_slot(msr);
+	slot = kvm_passthrough_msr_slot(msr);
 	WARN_ON(slot == -ENOENT);
 	if (slot >= 0) {
 		/* Set the shadow bitmaps to the desired intercept states */
@@ -871,7 +859,7 @@ void svm_enable_intercept_for_msr(struct kvm_vcpu *vcpu, u32 msr, int type)
 	struct vcpu_svm *svm = to_svm(vcpu);
 	int slot;
 
-	slot = direct_access_msr_slot(msr);
+	slot = kvm_passthrough_msr_slot(msr);
 	WARN_ON(slot == -ENOENT);
 	if (slot >= 0) {
 		/* Set the shadow bitmaps to the desired intercept states */
@@ -5165,6 +5153,8 @@ static struct kvm_x86_ops svm_x86_ops __initdata = {
 
 	.apic_init_signal_blocked = svm_apic_init_signal_blocked,
 
+	.possible_passthrough_msrs = direct_access_msrs,
+	.nr_possible_passthrough_msrs = ARRAY_SIZE(direct_access_msrs),
 	.msr_filter_changed = svm_msr_filter_changed,
 	.complete_emulated_msr = svm_complete_emulated_msr,
 
diff --git a/arch/x86/kvm/vmx/main.c b/arch/x86/kvm/vmx/main.c
index 92d35cc6cd15d..6d52693b0fd6c 100644
--- a/arch/x86/kvm/vmx/main.c
+++ b/arch/x86/kvm/vmx/main.c
@@ -7,6 +7,62 @@
 #include "pmu.h"
 #include "posted_intr.h"
 
+/*
+ * List of MSRs that can be directly passed to the guest.
+ * In addition to these x2apic, PT and LBR MSRs are handled specially.
+ */
+static const u32 vmx_possible_passthrough_msrs[] = {
+	MSR_IA32_SPEC_CTRL,
+	MSR_IA32_PRED_CMD,
+	MSR_IA32_FLUSH_CMD,
+	MSR_IA32_TSC,
+#ifdef CONFIG_X86_64
+	MSR_FS_BASE,
+	MSR_GS_BASE,
+	MSR_KERNEL_GS_BASE,
+	MSR_IA32_XFD,
+	MSR_IA32_XFD_ERR,
+#endif
+	MSR_IA32_SYSENTER_CS,
+	MSR_IA32_SYSENTER_ESP,
+	MSR_IA32_SYSENTER_EIP,
+	MSR_CORE_C1_RES,
+	MSR_CORE_C3_RESIDENCY,
+	MSR_CORE_C6_RESIDENCY,
+	MSR_CORE_C7_RESIDENCY,
+};
+
+void vmx_msr_filter_changed(struct kvm_vcpu *vcpu)
+{
+	struct vcpu_vmx *vmx = to_vmx(vcpu);
+	u32 i;
+
+	if (!cpu_has_vmx_msr_bitmap())
+		return;
+
+	/*
+	 * Redo intercept permissions for MSRs that KVM is passing through to
+	 * the guest.  Disabling interception will check the new MSR filter and
+	 * ensure that KVM enables interception if usersepace wants to filter
+	 * the MSR.  MSRs that KVM is already intercepting don't need to be
+	 * refreshed since KVM is going to intercept them regardless of what
+	 * userspace wants.
+	 */
+	for (i = 0; i < ARRAY_SIZE(vmx_possible_passthrough_msrs); i++) {
+		u32 msr = vmx_possible_passthrough_msrs[i];
+
+		if (!test_bit(i, vmx->shadow_msr_intercept.read))
+			vmx_disable_intercept_for_msr(vcpu, msr, MSR_TYPE_R);
+
+		if (!test_bit(i, vmx->shadow_msr_intercept.write))
+			vmx_disable_intercept_for_msr(vcpu, msr, MSR_TYPE_W);
+	}
+
+	/* PT MSRs can be passed through iff PT is exposed to the guest. */
+	if (vmx_pt_mode_is_host_guest())
+		pt_update_intercept_for_msr(vcpu);
+}
+
 #define VMX_REQUIRED_APICV_INHIBITS				\
 	(BIT(APICV_INHIBIT_REASON_DISABLED) |			\
 	 BIT(APICV_INHIBIT_REASON_ABSENT) |			\
@@ -152,6 +208,8 @@ struct kvm_x86_ops vt_x86_ops __initdata = {
 	.apic_init_signal_blocked = vmx_apic_init_signal_blocked,
 	.migrate_timers = vmx_migrate_timers,
 
+	.possible_passthrough_msrs = vmx_possible_passthrough_msrs,
+	.nr_possible_passthrough_msrs = ARRAY_SIZE(vmx_possible_passthrough_msrs),
 	.msr_filter_changed = vmx_msr_filter_changed,
 	.complete_emulated_msr = kvm_complete_insn_gp,
 
diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c
index bc64e7cc02704..1c2c0c06f3d35 100644
--- a/arch/x86/kvm/vmx/vmx.c
+++ b/arch/x86/kvm/vmx/vmx.c
@@ -163,31 +163,6 @@ module_param(allow_smaller_maxphyaddr, bool, S_IRUGO);
 	RTIT_STATUS_ERROR | RTIT_STATUS_STOPPED | \
 	RTIT_STATUS_BYTECNT))
 
-/*
- * List of MSRs that can be directly passed to the guest.
- * In addition to these x2apic, PT and LBR MSRs are handled specially.
- */
-static const u32 vmx_possible_passthrough_msrs[MAX_POSSIBLE_PASSTHROUGH_MSRS] = {
-	MSR_IA32_SPEC_CTRL,
-	MSR_IA32_PRED_CMD,
-	MSR_IA32_FLUSH_CMD,
-	MSR_IA32_TSC,
-#ifdef CONFIG_X86_64
-	MSR_FS_BASE,
-	MSR_GS_BASE,
-	MSR_KERNEL_GS_BASE,
-	MSR_IA32_XFD,
-	MSR_IA32_XFD_ERR,
-#endif
-	MSR_IA32_SYSENTER_CS,
-	MSR_IA32_SYSENTER_ESP,
-	MSR_IA32_SYSENTER_EIP,
-	MSR_CORE_C1_RES,
-	MSR_CORE_C3_RESIDENCY,
-	MSR_CORE_C6_RESIDENCY,
-	MSR_CORE_C7_RESIDENCY,
-};
-
 /*
  * These 2 parameters are used to config the controls for Pause-Loop Exiting:
  * ple_gap:    upper bound on the amount of time between two successive
@@ -669,7 +644,7 @@ static inline bool cpu_need_virtualize_apic_accesses(struct kvm_vcpu *vcpu)
 
 static int vmx_get_passthrough_msr_slot(u32 msr)
 {
-	int i;
+	int r;
 
 	switch (msr) {
 	case 0x800 ... 0x8ff:
@@ -692,13 +667,10 @@ static int vmx_get_passthrough_msr_slot(u32 msr)
 		return -ENOENT;
 	}
 
-	for (i = 0; i < ARRAY_SIZE(vmx_possible_passthrough_msrs); i++) {
-		if (vmx_possible_passthrough_msrs[i] == msr)
-			return i;
-	}
+	r = kvm_passthrough_msr_slot(msr);
 
-	WARN(1, "Invalid MSR %x, please adapt vmx_possible_passthrough_msrs[]", msr);
-	return -ENOENT;
+	WARN(!r, "Invalid MSR %x, please adapt vmx_possible_passthrough_msrs[]", msr);
+	return r;
 }
 
 struct vmx_uret_msr *vmx_find_uret_msr(struct vcpu_vmx *vmx, u32 msr)
@@ -4145,37 +4117,6 @@ void pt_update_intercept_for_msr(struct kvm_vcpu *vcpu)
 	}
 }
 
-void vmx_msr_filter_changed(struct kvm_vcpu *vcpu)
-{
-	struct vcpu_vmx *vmx = to_vmx(vcpu);
-	u32 i;
-
-	if (!cpu_has_vmx_msr_bitmap())
-		return;
-
-	/*
-	 * Redo intercept permissions for MSRs that KVM is passing through to
-	 * the guest.  Disabling interception will check the new MSR filter and
-	 * ensure that KVM enables interception if usersepace wants to filter
-	 * the MSR.  MSRs that KVM is already intercepting don't need to be
-	 * refreshed since KVM is going to intercept them regardless of what
-	 * userspace wants.
-	 */
-	for (i = 0; i < ARRAY_SIZE(vmx_possible_passthrough_msrs); i++) {
-		u32 msr = vmx_possible_passthrough_msrs[i];
-
-		if (!test_bit(i, vmx->shadow_msr_intercept.read))
-			vmx_disable_intercept_for_msr(vcpu, msr, MSR_TYPE_R);
-
-		if (!test_bit(i, vmx->shadow_msr_intercept.write))
-			vmx_disable_intercept_for_msr(vcpu, msr, MSR_TYPE_W);
-	}
-
-	/* PT MSRs can be passed through iff PT is exposed to the guest. */
-	if (vmx_pt_mode_is_host_guest())
-		pt_update_intercept_for_msr(vcpu);
-}
-
 static inline void kvm_vcpu_trigger_posted_interrupt(struct kvm_vcpu *vcpu,
 						     int pi_vec)
 {
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index 8637bc0010965..20b6cce793af5 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -1806,6 +1806,19 @@ bool kvm_msr_allowed(struct kvm_vcpu *vcpu, u32 index, u32 type)
 }
 EXPORT_SYMBOL_GPL(kvm_msr_allowed);
 
+int kvm_passthrough_msr_slot(u32 msr)
+{
+	u32 i;
+
+	for (i = 0; i < kvm_x86_ops.nr_possible_passthrough_msrs; i++) {
+		if (kvm_x86_ops.possible_passthrough_msrs[i] == msr)
+			return i;
+	}
+
+	return -ENOENT;
+}
+EXPORT_SYMBOL_GPL(kvm_passthrough_msr_slot);
+
 /*
  * Write @data into the MSR specified by @index.  Select MSR specific fault
  * checks are bypassed if @host_initiated is %true.
diff --git a/arch/x86/kvm/x86.h b/arch/x86/kvm/x86.h
index ec623d23d13d2..208f0698c64e2 100644
--- a/arch/x86/kvm/x86.h
+++ b/arch/x86/kvm/x86.h
@@ -555,6 +555,7 @@ int kvm_handle_memory_failure(struct kvm_vcpu *vcpu, int r,
 			      struct x86_exception *e);
 int kvm_handle_invpcid(struct kvm_vcpu *vcpu, unsigned long type, gva_t gva);
 bool kvm_msr_allowed(struct kvm_vcpu *vcpu, u32 index, u32 type);
+int kvm_passthrough_msr_slot(u32 msr);
 
 enum kvm_msr_access {
 	MSR_TYPE_R	= BIT(0),
-- 
2.47.0.338.g60cca15819-goog