KVM: x86 emulator: implement RDPMC (0F 33)

Signed-off-by: NAvi Kivity <avi@redhat.com>
Signed-off-by: NGleb Natapov <gleb@redhat.com>
Signed-off-by: NAvi Kivity <avi@redhat.com>

arch/x86/include/asm/kvm_emulate.h

@@ -181,6 +181,7 @@ struct x86_emulate_ops {
 	int (*set_dr)(struct x86_emulate_ctxt *ctxt, int dr, ulong value);
 	int (*set_msr)(struct x86_emulate_ctxt *ctxt, u32 msr_index, u64 data);
 	int (*get_msr)(struct x86_emulate_ctxt *ctxt, u32 msr_index, u64 *pdata);
+	int (*read_pmc)(struct x86_emulate_ctxt *ctxt, u32 pmc, u64 *pdata);
 	void (*halt)(struct x86_emulate_ctxt *ctxt);
 	void (*wbinvd)(struct x86_emulate_ctxt *ctxt);
 	int (*fix_hypercall)(struct x86_emulate_ctxt *ctxt);

arch/x86/kvm/emulate.c

@@ -2645,6 +2645,17 @@ static int em_rdtsc(struct x86_emulate_ctxt *ctxt)
 	return X86EMUL_CONTINUE;
 }
 
+static int em_rdpmc(struct x86_emulate_ctxt *ctxt)
+{
+	u64 pmc;
+
+	if (ctxt->ops->read_pmc(ctxt, ctxt->regs[VCPU_REGS_RCX], &pmc))
+		return emulate_gp(ctxt, 0);
+	ctxt->regs[VCPU_REGS_RAX] = (u32)pmc;
+	ctxt->regs[VCPU_REGS_RDX] = pmc >> 32;
+	return X86EMUL_CONTINUE;
+}
+
 static int em_mov(struct x86_emulate_ctxt *ctxt)
 {
 	ctxt->dst.val = ctxt->src.val;
@@ -3411,7 +3422,7 @@ static struct opcode twobyte_table[256] = {
 	II(ImplicitOps | Priv, em_wrmsr, wrmsr),
 	IIP(ImplicitOps, em_rdtsc, rdtsc, check_rdtsc),
 	II(ImplicitOps | Priv, em_rdmsr, rdmsr),
-	DIP(ImplicitOps, rdpmc, check_rdpmc),
+	IIP(ImplicitOps, em_rdpmc, rdpmc, check_rdpmc),
 	I(ImplicitOps | VendorSpecific, em_sysenter),
 	I(ImplicitOps | Priv | VendorSpecific, em_sysexit),
 	N, N,

arch/x86/kvm/x86.c

@@ -4146,6 +4146,12 @@ static int emulator_set_msr(struct x86_emulate_ctxt *ctxt,
 	return kvm_set_msr(emul_to_vcpu(ctxt), msr_index, data);
 }
 
+static int emulator_read_pmc(struct x86_emulate_ctxt *ctxt,
+			     u32 pmc, u64 *pdata)
+{
+	return kvm_pmu_read_pmc(emul_to_vcpu(ctxt), pmc, pdata);
+}
+
 static void emulator_halt(struct x86_emulate_ctxt *ctxt)
 {
 	emul_to_vcpu(ctxt)->arch.halt_request = 1;
@@ -4198,6 +4204,7 @@ static struct x86_emulate_ops emulate_ops = {
 	.set_dr              = emulator_set_dr,
 	.set_msr             = emulator_set_msr,
 	.get_msr             = emulator_get_msr,
+	.read_pmc            = emulator_read_pmc,
 	.halt                = emulator_halt,
 	.wbinvd              = emulator_wbinvd,
 	.fix_hypercall       = emulator_fix_hypercall,