KVM: x86: Update vPMCs when retiring branch instructions

When KVM retires a guest branch instruction through emulation,
increment any vPMCs that are configured to monitor "branch
instructions retired," and update the sample period of those counters
so that they will overflow at the right time.

Signed-off-by: Eric Hankland <ehankland@google.com>
[jmattson:
  - Split the code to increment "branch instructions retired" into a
    separate commit.
  - Moved/consolidated the calls to kvm_pmu_trigger_event() in the
    emulation of VMLAUNCH/VMRESUME to accommodate the evolution of
    that code.
]
Fixes: f5132b01386b ("KVM: Expose a version 2 architectural PMU to a guests")
Signed-off-by: Jim Mattson <jmattson@google.com>
Message-Id: <20211130074221.93635-7-likexu@tencent.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

1 files changed, 31 insertions, 24 deletions

diff --git a/arch/x86/kvm/emulate.c b/arch/x86/kvm/emulate.c
index 28b1a4e57827..166a145fc1e6 100644
--- a/arch/x86/kvm/emulate.c
+++ b/arch/x86/kvm/emulate.c
@@ -175,6 +175,7 @@
 #define No16	    ((u64)1 << 53)  /* No 16 bit operand */
 #define IncSP       ((u64)1 << 54)  /* SP is incremented before ModRM calc */
 #define TwoMemOp    ((u64)1 << 55)  /* Instruction has two memory operand */
+#define IsBranch    ((u64)1 << 56)  /* Instruction is considered a branch. */
 
 #define DstXacc     (DstAccLo | SrcAccHi | SrcWrite)
 
@@ -191,8 +192,9 @@
 #define FASTOP_SIZE 8
 
 struct opcode {
-	u64 flags : 56;
-	u64 intercept : 8;
+	u64 flags;
+	u8 intercept;
+	u8 pad[7];
 	union {
 		int (*execute)(struct x86_emulate_ctxt *ctxt);
 		const struct opcode *group;
@@ -4364,10 +4366,10 @@ static const struct opcode group4[] = {
 static const struct opcode group5[] = {
 	F(DstMem | SrcNone | Lock,		em_inc),
 	F(DstMem | SrcNone | Lock,		em_dec),
-	I(SrcMem | NearBranch,			em_call_near_abs),
-	I(SrcMemFAddr | ImplicitOps,		em_call_far),
-	I(SrcMem | NearBranch,			em_jmp_abs),
-	I(SrcMemFAddr | ImplicitOps,		em_jmp_far),
+	I(SrcMem | NearBranch | IsBranch,       em_call_near_abs),
+	I(SrcMemFAddr | ImplicitOps | IsBranch, em_call_far),
+	I(SrcMem | NearBranch | IsBranch,       em_jmp_abs),
+	I(SrcMemFAddr | ImplicitOps | IsBranch, em_jmp_far),
 	I(SrcMem | Stack | TwoMemOp,		em_push), D(Undefined),
 };
 
@@ -4577,7 +4579,7 @@ static const struct opcode opcode_table[256] = {
 	I2bvIP(DstDI | SrcDX | Mov | String | Unaligned, em_in, ins, check_perm_in), /* insb, insw/insd */
 	I2bvIP(SrcSI | DstDX | String, em_out, outs, check_perm_out), /* outsb, outsw/outsd */
 	/* 0x70 - 0x7F */
-	X16(D(SrcImmByte | NearBranch)),
+	X16(D(SrcImmByte | NearBranch | IsBranch)),
 	/* 0x80 - 0x87 */
 	G(ByteOp | DstMem | SrcImm, group1),
 	G(DstMem | SrcImm, group1),
@@ -4596,7 +4598,7 @@ static const struct opcode opcode_table[256] = {
 	DI(SrcAcc | DstReg, pause), X7(D(SrcAcc | DstReg)),
 	/* 0x98 - 0x9F */
 	D(DstAcc | SrcNone), I(ImplicitOps | SrcAcc, em_cwd),
-	I(SrcImmFAddr | No64, em_call_far), N,
+	I(SrcImmFAddr | No64 | IsBranch, em_call_far), N,
 	II(ImplicitOps | Stack, em_pushf, pushf),
 	II(ImplicitOps | Stack, em_popf, popf),
 	I(ImplicitOps, em_sahf), I(ImplicitOps, em_lahf),
@@ -4616,17 +4618,19 @@ static const struct opcode opcode_table[256] = {
 	X8(I(DstReg | SrcImm64 | Mov, em_mov)),
 	/* 0xC0 - 0xC7 */
 	G(ByteOp | Src2ImmByte, group2), G(Src2ImmByte, group2),
-	I(ImplicitOps | NearBranch | SrcImmU16, em_ret_near_imm),
-	I(ImplicitOps | NearBranch, em_ret),
+	I(ImplicitOps | NearBranch | SrcImmU16 | IsBranch, em_ret_near_imm),
+	I(ImplicitOps | NearBranch | IsBranch, em_ret),
 	I(DstReg | SrcMemFAddr | ModRM | No64 | Src2ES, em_lseg),
 	I(DstReg | SrcMemFAddr | ModRM | No64 | Src2DS, em_lseg),
 	G(ByteOp, group11), G(0, group11),
 	/* 0xC8 - 0xCF */
-	I(Stack | SrcImmU16 | Src2ImmByte, em_enter), I(Stack, em_leave),
-	I(ImplicitOps | SrcImmU16, em_ret_far_imm),
-	I(ImplicitOps, em_ret_far),
-	D(ImplicitOps), DI(SrcImmByte, intn),
-	D(ImplicitOps | No64), II(ImplicitOps, em_iret, iret),
+	I(Stack | SrcImmU16 | Src2ImmByte | IsBranch, em_enter),
+	I(Stack | IsBranch, em_leave),
+	I(ImplicitOps | SrcImmU16 | IsBranch, em_ret_far_imm),
+	I(ImplicitOps | IsBranch, em_ret_far),
+	D(ImplicitOps | IsBranch), DI(SrcImmByte | IsBranch, intn),
+	D(ImplicitOps | No64 | IsBranch),
+	II(ImplicitOps | IsBranch, em_iret, iret),
 	/* 0xD0 - 0xD7 */
 	G(Src2One | ByteOp, group2), G(Src2One, group2),
 	G(Src2CL | ByteOp, group2), G(Src2CL, group2),
@@ -4637,14 +4641,15 @@ static const struct opcode opcode_table[256] = {
 	/* 0xD8 - 0xDF */
 	N, E(0, &escape_d9), N, E(0, &escape_db), N, E(0, &escape_dd), N, N,
 	/* 0xE0 - 0xE7 */
-	X3(I(SrcImmByte | NearBranch, em_loop)),
-	I(SrcImmByte | NearBranch, em_jcxz),
+	X3(I(SrcImmByte | NearBranch | IsBranch, em_loop)),
+	I(SrcImmByte | NearBranch | IsBranch, em_jcxz),
 	I2bvIP(SrcImmUByte | DstAcc, em_in,  in,  check_perm_in),
 	I2bvIP(SrcAcc | DstImmUByte, em_out, out, check_perm_out),
 	/* 0xE8 - 0xEF */
-	I(SrcImm | NearBranch, em_call), D(SrcImm | ImplicitOps | NearBranch),
-	I(SrcImmFAddr | No64, em_jmp_far),
-	D(SrcImmByte | ImplicitOps | NearBranch),
+	I(SrcImm | NearBranch | IsBranch, em_call),
+	D(SrcImm | ImplicitOps | NearBranch | IsBranch),
+	I(SrcImmFAddr | No64 | IsBranch, em_jmp_far),
+	D(SrcImmByte | ImplicitOps | NearBranch | IsBranch),
 	I2bvIP(SrcDX | DstAcc, em_in,  in,  check_perm_in),
 	I2bvIP(SrcAcc | DstDX, em_out, out, check_perm_out),
 	/* 0xF0 - 0xF7 */
@@ -4660,7 +4665,7 @@ static const struct opcode opcode_table[256] = {
 static const struct opcode twobyte_table[256] = {
 	/* 0x00 - 0x0F */
 	G(0, group6), GD(0, &group7), N, N,
-	N, I(ImplicitOps | EmulateOnUD, em_syscall),
+	N, I(ImplicitOps | EmulateOnUD | IsBranch, em_syscall),
 	II(ImplicitOps | Priv, em_clts, clts), N,
 	DI(ImplicitOps | Priv, invd), DI(ImplicitOps | Priv, wbinvd), N, N,
 	N, D(ImplicitOps | ModRM | SrcMem | NoAccess), N, N,
@@ -4691,8 +4696,8 @@ static const struct opcode twobyte_table[256] = {
 	IIP(ImplicitOps, em_rdtsc, rdtsc, check_rdtsc),
 	II(ImplicitOps | Priv, em_rdmsr, rdmsr),
 	IIP(ImplicitOps, em_rdpmc, rdpmc, check_rdpmc),
-	I(ImplicitOps | EmulateOnUD, em_sysenter),
-	I(ImplicitOps | Priv | EmulateOnUD, em_sysexit),
+	I(ImplicitOps | EmulateOnUD | IsBranch, em_sysenter),
+	I(ImplicitOps | Priv | EmulateOnUD | IsBranch, em_sysexit),
 	N, N,
 	N, N, N, N, N, N, N, N,
 	/* 0x40 - 0x4F */
@@ -4710,7 +4715,7 @@ static const struct opcode twobyte_table[256] = {
 	N, N, N, N,
 	N, N, N, GP(SrcReg | DstMem | ModRM | Mov, &pfx_0f_6f_0f_7f),
 	/* 0x80 - 0x8F */
-	X16(D(SrcImm | NearBranch)),
+	X16(D(SrcImm | NearBranch | IsBranch)),
 	/* 0x90 - 0x9F */
 	X16(D(ByteOp | DstMem | SrcNone | ModRM| Mov)),
 	/* 0xA0 - 0xA7 */
@@ -5224,6 +5229,8 @@ done_prefixes:
 		ctxt->d |= opcode.flags;
 	}
 
+	ctxt->is_branch = opcode.flags & IsBranch;
+
 	/* Unrecognised? */
 	if (ctxt->d == 0)
 		return EMULATION_FAILED;