[PATCH v3 03/12] KVM: x86: Encapsulate VMware backdoor checks

[Zack Rusin <zack.rusin@broadcom.com>]

Add kvm_is_vmware_backdoor_enabled(), kvm_is_vmware_io_port(),
kvm_is_vmware_backdoor_pmc() and kvm_is_vmware_backdoor_opcode(), and
use them instead of checking enable_vmware_backdoor and the VMware port
and pseudo-PMC numbers directly.  Make the module parameter and the
pseudo-PMC numbers private to vmware.c, and take the backdoor port
numbers from <asm/vmware.h> instead of keeping a second copy.

The next patches make the backdoor a per-VM setting.  With every caller
asking whether a vCPU accepts a VMware interface, instead of reading a
global, that change stays inside vmware.c.

Check the enabled state inside the port and pseudo-PMC predicates, so
that no caller can treat a port or PMC index as VMware's for a VM that
hasn't enabled the backdoor.

No functional change intended.

Suggested-by: Sean Christopherson <seanjc@google.com>
Link: https://lore.kernel.org/r/aIEgVpjXDR0BXgHq@google.com
Signed-off-by: Zack Rusin <zack.rusin@broadcom.com>
---
 arch/x86/kvm/emulate.c |  5 +--
 arch/x86/kvm/pmu.c     |  6 +--
 arch/x86/kvm/svm/svm.c |  6 +--
 arch/x86/kvm/vmware.c  | 92 +++++++++++++++++++++++++-----------------
 arch/x86/kvm/vmware.h  | 19 +++------
 arch/x86/kvm/vmx/vmx.c |  4 +-
 arch/x86/kvm/x86.c     |  2 +-
 7 files changed, 72 insertions(+), 62 deletions(-)

diff --git a/arch/x86/kvm/emulate.c b/arch/x86/kvm/emulate.c
index a7bcde6f0359..da626bed93c5 100644
--- a/arch/x86/kvm/emulate.c
+++ b/arch/x86/kvm/emulate.c
@@ -2539,8 +2539,7 @@ static bool emulator_io_port_access_allowed(struct x86_emulate_ctxt *ctxt,
 	 * VMware allows access to these ports even if denied
 	 * by TSS I/O permission bitmap. Mimic behavior.
 	 */
-	if (enable_vmware_backdoor &&
-	    ((port == VMWARE_PORT_VMPORT) || (port == VMWARE_PORT_VMRPC)))
+	if (kvm_is_vmware_io_port(ctxt->vcpu, port))
 		return true;
 
 	ops->get_segment(ctxt, &tr, &tr_seg, &base3, VCPU_SREG_TR);
@@ -3908,7 +3907,7 @@ static int check_rdpmc(struct x86_emulate_ctxt *ctxt)
 	 * VMware allows access to these Pseduo-PMCs even when read via RDPMC
 	 * in Ring3 when CR4.PCE=0.
 	 */
-	if (enable_vmware_backdoor && is_vmware_backdoor_pmc(rcx))
+	if (kvm_is_vmware_backdoor_pmc(ctxt->vcpu, rcx))
 		return X86EMUL_CONTINUE;
 
 	/*
diff --git a/arch/x86/kvm/pmu.c b/arch/x86/kvm/pmu.c
index ae7000c44677..dacd40ca8620 100644
--- a/arch/x86/kvm/pmu.c
+++ b/arch/x86/kvm/pmu.c
@@ -726,8 +726,8 @@ int kvm_pmu_rdpmc(struct kvm_vcpu *vcpu, unsigned idx, u64 *data)
 	if (!pmu->version)
 		return 1;
 
-	if (enable_vmware_backdoor && is_vmware_backdoor_pmc(idx))
-		return kvm_pmu_rdpmc_vmware(vcpu, idx, data);
+	if (kvm_is_vmware_backdoor_pmc(vcpu, idx))
+		return kvm_vmware_pmu_rdpmc(vcpu, idx, data);
 
 	pmc = kvm_pmu_call(rdpmc_ecx_to_pmc)(vcpu, idx, &mask);
 	if (!pmc)
@@ -773,7 +773,7 @@ bool kvm_need_rdpmc_intercept(struct kvm_vcpu *vcpu)
 	 * VMware allows access to these Pseduo-PMCs even when read via RDPMC
 	 * in Ring3 when CR4.PCE=0.
 	 */
-	if (enable_vmware_backdoor)
+	if (kvm_is_vmware_backdoor_enabled(vcpu))
 		return true;
 
 	return kvm_need_any_pmc_intercept(vcpu) ||
diff --git a/arch/x86/kvm/svm/svm.c b/arch/x86/kvm/svm/svm.c
index 980841d153f3..a2196d8f60aa 100644
--- a/arch/x86/kvm/svm/svm.c
+++ b/arch/x86/kvm/svm/svm.c
@@ -237,7 +237,7 @@ int svm_set_efer(struct kvm_vcpu *vcpu, u64 efer)
 
 			svm_leave_nested(vcpu);
 			/* #GP intercept is still needed for vmware backdoor */
-			if (!enable_vmware_backdoor)
+			if (!kvm_is_vmware_backdoor_enabled(vcpu))
 				clr_exception_intercept(svm, GP_VECTOR);
 
 			/*
@@ -1159,7 +1159,7 @@ static void init_vmcb(struct kvm_vcpu *vcpu, bool init_event)
 	 * We intercept those #GP and allow access to them anyway
 	 * as VMware does.
 	 */
-	if (enable_vmware_backdoor)
+	if (kvm_is_vmware_backdoor_enabled(vcpu))
 		set_exception_intercept(svm, GP_VECTOR);
 
 	svm_set_intercept(svm, INTERCEPT_INTR);
@@ -2410,7 +2410,7 @@ static int gp_interception(struct kvm_vcpu *vcpu)
 	 * VMware backdoor emulation on #GP interception only handles
 	 * IN{S}, OUT{S}, and RDPMC, and only for L1.
 	 */
-	if (!enable_vmware_backdoor || is_guest_mode(vcpu))
+	if (!kvm_is_vmware_backdoor_enabled(vcpu) || is_guest_mode(vcpu))
 		goto reinject;
 
 	return kvm_emulate_instruction(vcpu, EMULTYPE_VMWARE_GP | EMULTYPE_NO_DECODE);
diff --git a/arch/x86/kvm/vmware.c b/arch/x86/kvm/vmware.c
index 772f295f8ff5..e1062144b750 100644
--- a/arch/x86/kvm/vmware.c
+++ b/arch/x86/kvm/vmware.c
@@ -8,15 +8,35 @@
 
 #include <linux/moduleparam.h>
 
-#include "kvm_emulate.h"
+#include <asm/vmware.h>
+
 #include "vmware.h"
 
-bool __read_mostly enable_vmware_backdoor;
-EXPORT_SYMBOL_FOR_KVM_INTERNAL(enable_vmware_backdoor);
+static bool __read_mostly enable_vmware_backdoor;
 module_param(enable_vmware_backdoor, bool, 0444);
 
-bool is_vmware_backdoor_pmc(u32 pmc_idx)
+#define VMWARE_BACKDOOR_PMC_HOST_TSC		0x10000
+#define VMWARE_BACKDOOR_PMC_REAL_TIME		0x10001
+#define VMWARE_BACKDOOR_PMC_APPARENT_TIME	0x10002
+
+bool kvm_is_vmware_backdoor_enabled(struct kvm_vcpu *vcpu)
 {
+	return enable_vmware_backdoor;
+}
+EXPORT_SYMBOL_FOR_KVM_INTERNAL(kvm_is_vmware_backdoor_enabled);
+
+bool kvm_is_vmware_io_port(struct kvm_vcpu *vcpu, u16 port)
+{
+	return kvm_is_vmware_backdoor_enabled(vcpu) &&
+	       (port == VMWARE_HYPERVISOR_PORT ||
+		port == VMWARE_HYPERVISOR_PORT_HB);
+}
+
+bool kvm_is_vmware_backdoor_pmc(struct kvm_vcpu *vcpu, u32 pmc_idx)
+{
+	if (!kvm_is_vmware_backdoor_enabled(vcpu))
+		return false;
+
 	switch (pmc_idx) {
 	case VMWARE_BACKDOOR_PMC_HOST_TSC:
 	case VMWARE_BACKDOOR_PMC_REAL_TIME:
@@ -26,7 +46,38 @@ bool is_vmware_backdoor_pmc(u32 pmc_idx)
 	return false;
 }
 
-int kvm_pmu_rdpmc_vmware(struct kvm_vcpu *vcpu, unsigned int idx, u64 *data)
+bool kvm_is_vmware_backdoor_opcode(u8 opcode_len, u8 opcode)
+{
+	switch (opcode_len) {
+	case 1:
+		switch (opcode) {
+		case 0xe4:	/* IN */
+		case 0xe5:
+		case 0xec:
+		case 0xed:
+		case 0xe6:	/* OUT */
+		case 0xe7:
+		case 0xee:
+		case 0xef:
+		case 0x6c:	/* INS */
+		case 0x6d:
+		case 0x6e:	/* OUTS */
+		case 0x6f:
+			return true;
+		}
+		break;
+	case 2:
+		switch (opcode) {
+		case 0x33:	/* RDPMC */
+			return true;
+		}
+		break;
+	}
+
+	return false;
+}
+
+int kvm_vmware_pmu_rdpmc(struct kvm_vcpu *vcpu, unsigned int idx, u64 *data)
 {
 	u64 ctr_val;
 
@@ -48,34 +99,3 @@ int kvm_pmu_rdpmc_vmware(struct kvm_vcpu *vcpu, unsigned int idx, u64 *data)
 	*data = ctr_val;
 	return 0;
 }
-
-bool is_vmware_backdoor_opcode(struct x86_emulate_ctxt *ctxt)
-{
-	switch (ctxt->opcode_len) {
-	case 1:
-		switch (ctxt->b) {
-		case 0xe4:	/* IN */
-		case 0xe5:
-		case 0xec:
-		case 0xed:
-		case 0xe6:	/* OUT */
-		case 0xe7:
-		case 0xee:
-		case 0xef:
-		case 0x6c:	/* INS */
-		case 0x6d:
-		case 0x6e:	/* OUTS */
-		case 0x6f:
-			return true;
-		}
-		break;
-	case 2:
-		switch (ctxt->b) {
-		case 0x33:	/* RDPMC */
-			return true;
-		}
-		break;
-	}
-
-	return false;
-}
diff --git a/arch/x86/kvm/vmware.h b/arch/x86/kvm/vmware.h
index debabaff9654..bf250cc6e232 100644
--- a/arch/x86/kvm/vmware.h
+++ b/arch/x86/kvm/vmware.h
@@ -4,19 +4,10 @@
 
 #include <linux/kvm_host.h>
 
-struct x86_emulate_ctxt;
-
-#define VMWARE_BACKDOOR_PMC_HOST_TSC		0x10000
-#define VMWARE_BACKDOOR_PMC_REAL_TIME		0x10001
-#define VMWARE_BACKDOOR_PMC_APPARENT_TIME	0x10002
-
-#define VMWARE_PORT_VMPORT	(0x5658)
-#define VMWARE_PORT_VMRPC	(0x5659)
-
-extern bool enable_vmware_backdoor;
-
-bool is_vmware_backdoor_pmc(u32 pmc_idx);
-int kvm_pmu_rdpmc_vmware(struct kvm_vcpu *vcpu, unsigned int idx, u64 *data);
-bool is_vmware_backdoor_opcode(struct x86_emulate_ctxt *ctxt);
+bool kvm_is_vmware_backdoor_enabled(struct kvm_vcpu *vcpu);
+bool kvm_is_vmware_io_port(struct kvm_vcpu *vcpu, u16 port);
+bool kvm_is_vmware_backdoor_pmc(struct kvm_vcpu *vcpu, u32 pmc_idx);
+bool kvm_is_vmware_backdoor_opcode(u8 opcode_len, u8 opcode);
+int kvm_vmware_pmu_rdpmc(struct kvm_vcpu *vcpu, unsigned int idx, u64 *data);
 
 #endif /* __KVM_X86_VMWARE_H */
diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c
index d407eecf1034..edcc5714cb6f 100644
--- a/arch/x86/kvm/vmx/vmx.c
+++ b/arch/x86/kvm/vmx/vmx.c
@@ -918,7 +918,7 @@ void vmx_update_exception_bitmap(struct kvm_vcpu *vcpu)
 	 * We intercept those #GP and allow access to them anyway
 	 * as VMware does.
 	 */
-	if (enable_vmware_backdoor)
+	if (kvm_is_vmware_backdoor_enabled(vcpu))
 		eb |= (1u << GP_VECTOR);
 	if ((vcpu->guest_debug &
 	     (KVM_GUESTDBG_ENABLE | KVM_GUESTDBG_USE_SW_BP)) ==
@@ -5483,7 +5483,7 @@ static int handle_exception_nmi(struct kvm_vcpu *vcpu)
 		error_code = vmcs_read32(VM_EXIT_INTR_ERROR_CODE);
 
 	if (!vmx->rmode.vm86_active && is_gp_fault(intr_info)) {
-		WARN_ON_ONCE(!enable_vmware_backdoor);
+		WARN_ON_ONCE(!kvm_is_vmware_backdoor_enabled(vcpu));
 
 		/*
 		 * VMware backdoor emulation on #GP interception only handles
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index 389ae6213c85..0548e34bf634 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -6402,7 +6402,7 @@ int x86_emulate_instruction(struct kvm_vcpu *vcpu, gpa_t cr2_or_gpa,
 	}
 
 	if ((emulation_type & EMULTYPE_VMWARE_GP) &&
-	    !is_vmware_backdoor_opcode(ctxt)) {
+	    !kvm_is_vmware_backdoor_opcode(ctxt->opcode_len, ctxt->b)) {
 		kvm_queue_exception_e(vcpu, GP_VECTOR, 0);
 		return 1;
 	}
-- 
2.53.0