From d5ae7ce835cc89556dc18e2070e754f026402efa Mon Sep 17 00:00:00 2001 From: Xiao Guangrong Date: Thu, 22 Sep 2011 16:53:46 +0800 Subject: [PATCH] KVM: x86: tag the instructions which are used to write page table The idea is from Avi: | tag instructions that are typically used to modify the page tables, and | drop shadow if any other instruction is used. | The list would include, I'd guess, and, or, bts, btc, mov, xchg, cmpxchg, | and cmpxchg8b. This patch is used to tag the instructions and in the later path, shadow page is dropped if it is written by other instructions Signed-off-by: Xiao Guangrong Signed-off-by: Avi Kivity --- arch/x86/kvm/emulate.c | 37 +++++++++++++++++++++---------------- 1 file changed, 21 insertions(+), 16 deletions(-) diff --git a/arch/x86/kvm/emulate.c b/arch/x86/kvm/emulate.c index f1e3be18..a10950a 100644 --- a/arch/x86/kvm/emulate.c +++ b/arch/x86/kvm/emulate.c @@ -125,8 +125,9 @@ #define Lock (1<<26) /* lock prefix is allowed for the instruction */ #define Priv (1<<27) /* instruction generates #GP if current CPL != 0 */ #define No64 (1<<28) +#define PageTable (1 << 29) /* instruction used to write page table */ /* Source 2 operand type */ -#define Src2Shift (29) +#define Src2Shift (30) #define Src2None (OpNone << Src2Shift) #define Src2CL (OpCL << Src2Shift) #define Src2ImmByte (OpImmByte << Src2Shift) @@ -3033,10 +3034,10 @@ static struct opcode group7_rm7[] = { static struct opcode group1[] = { I(Lock, em_add), - I(Lock, em_or), + I(Lock | PageTable, em_or), I(Lock, em_adc), I(Lock, em_sbb), - I(Lock, em_and), + I(Lock | PageTable, em_and), I(Lock, em_sub), I(Lock, em_xor), I(0, em_cmp), @@ -3096,18 +3097,21 @@ static struct group_dual group7 = { { static struct opcode group8[] = { N, N, N, N, - D(DstMem | SrcImmByte | ModRM), D(DstMem | SrcImmByte | ModRM | Lock), - D(DstMem | SrcImmByte | ModRM | Lock), D(DstMem | SrcImmByte | ModRM | Lock), + D(DstMem | SrcImmByte | ModRM), + D(DstMem | SrcImmByte | ModRM | Lock | PageTable), + D(DstMem | SrcImmByte | ModRM | Lock), + D(DstMem | SrcImmByte | ModRM | Lock | PageTable), }; static struct group_dual group9 = { { - N, D(DstMem64 | ModRM | Lock), N, N, N, N, N, N, + N, D(DstMem64 | ModRM | Lock | PageTable), N, N, N, N, N, N, }, { N, N, N, N, N, N, N, N, } }; static struct opcode group11[] = { - I(DstMem | SrcImm | ModRM | Mov, em_mov), X7(D(Undefined)), + I(DstMem | SrcImm | ModRM | Mov | PageTable, em_mov), + X7(D(Undefined)), }; static struct gprefix pfx_0f_6f_0f_7f = { @@ -3120,7 +3124,7 @@ static struct opcode opcode_table[256] = { I(ImplicitOps | Stack | No64 | Src2ES, em_push_sreg), I(ImplicitOps | Stack | No64 | Src2ES, em_pop_sreg), /* 0x08 - 0x0F */ - I6ALU(Lock, em_or), + I6ALU(Lock | PageTable, em_or), I(ImplicitOps | Stack | No64 | Src2CS, em_push_sreg), N, /* 0x10 - 0x17 */ @@ -3132,7 +3136,7 @@ static struct opcode opcode_table[256] = { I(ImplicitOps | Stack | No64 | Src2DS, em_push_sreg), I(ImplicitOps | Stack | No64 | Src2DS, em_pop_sreg), /* 0x20 - 0x27 */ - I6ALU(Lock, em_and), N, N, + I6ALU(Lock | PageTable, em_and), N, N, /* 0x28 - 0x2F */ I6ALU(Lock, em_sub), N, I(ByteOp | DstAcc | No64, em_das), /* 0x30 - 0x37 */ @@ -3165,11 +3169,11 @@ static struct opcode opcode_table[256] = { G(ByteOp | DstMem | SrcImm | ModRM | No64 | Group, group1), G(DstMem | SrcImmByte | ModRM | Group, group1), I2bv(DstMem | SrcReg | ModRM, em_test), - I2bv(DstMem | SrcReg | ModRM | Lock, em_xchg), + I2bv(DstMem | SrcReg | ModRM | Lock | PageTable, em_xchg), /* 0x88 - 0x8F */ - I2bv(DstMem | SrcReg | ModRM | Mov, em_mov), + I2bv(DstMem | SrcReg | ModRM | Mov | PageTable, em_mov), I2bv(DstReg | SrcMem | ModRM | Mov, em_mov), - I(DstMem | SrcNone | ModRM | Mov, em_mov_rm_sreg), + I(DstMem | SrcNone | ModRM | Mov | PageTable, em_mov_rm_sreg), D(ModRM | SrcMem | NoAccess | DstReg), I(ImplicitOps | SrcMem16 | ModRM, em_mov_sreg_rm), G(0, group1A), @@ -3182,7 +3186,7 @@ static struct opcode opcode_table[256] = { II(ImplicitOps | Stack, em_popf, popf), N, N, /* 0xA0 - 0xA7 */ I2bv(DstAcc | SrcMem | Mov | MemAbs, em_mov), - I2bv(DstMem | SrcAcc | Mov | MemAbs, em_mov), + I2bv(DstMem | SrcAcc | Mov | MemAbs | PageTable, em_mov), I2bv(SrcSI | DstDI | Mov | String, em_mov), I2bv(SrcSI | DstDI | String, em_cmp), /* 0xA8 - 0xAF */ @@ -3280,12 +3284,13 @@ static struct opcode twobyte_table[256] = { D(DstMem | SrcReg | Src2CL | ModRM), N, N, /* 0xA8 - 0xAF */ I(Stack | Src2GS, em_push_sreg), I(Stack | Src2GS, em_pop_sreg), - DI(ImplicitOps, rsm), D(DstMem | SrcReg | ModRM | BitOp | Lock), + DI(ImplicitOps, rsm), + D(DstMem | SrcReg | ModRM | BitOp | Lock | PageTable), D(DstMem | SrcReg | Src2ImmByte | ModRM), D(DstMem | SrcReg | Src2CL | ModRM), D(ModRM), I(DstReg | SrcMem | ModRM, em_imul), /* 0xB0 - 0xB7 */ - D2bv(DstMem | SrcReg | ModRM | Lock), + D2bv(DstMem | SrcReg | ModRM | Lock | PageTable), I(DstReg | SrcMemFAddr | ModRM | Src2SS, em_lseg), D(DstMem | SrcReg | ModRM | BitOp | Lock), I(DstReg | SrcMemFAddr | ModRM | Src2FS, em_lseg), @@ -3293,7 +3298,7 @@ static struct opcode twobyte_table[256] = { D(ByteOp | DstReg | SrcMem | ModRM | Mov), D(DstReg | SrcMem16 | ModRM | Mov), /* 0xB8 - 0xBF */ N, N, - G(BitOp, group8), D(DstMem | SrcReg | ModRM | BitOp | Lock), + G(BitOp, group8), D(DstMem | SrcReg | ModRM | BitOp | Lock | PageTable), D(DstReg | SrcMem | ModRM), D(DstReg | SrcMem | ModRM), D(ByteOp | DstReg | SrcMem | ModRM | Mov), D(DstReg | SrcMem16 | ModRM | Mov), /* 0xC0 - 0xCF */ -- 2.7.4