78 lines
2.5 KiB
Diff
78 lines
2.5 KiB
Diff
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From: Nadav Amit <namit@cs.technion.ac.il>
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Date: Fri, 24 Oct 2014 17:07:22 +0200
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Subject: [PATCH] KVM: x86: Emulator does not decode clflush well
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Currently, all group15 instructions are decoded as clflush (e.g., mfence,
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xsave). In addition, the clflush instruction requires no prefix (66/f2/f3)
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would exist. If prefix exists it may encode a different instruction (e.g.,
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clflushopt).
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Creating a group for clflush, and different group for each prefix.
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This has been the case forever, but the next patch needs the cflush group
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in order to fix a bug introduced in 3.17.
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Fixes: 41061cdb98a0bec464278b4db8e894a3121671f5
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Cc: stable@vger.kernel.org
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Signed-off-by: Nadav Amit <namit@cs.technion.ac.il>
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Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
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---
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arch/x86/kvm/emulate.c | 20 +++++++++++++++++---
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1 file changed, 17 insertions(+), 3 deletions(-)
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diff --git a/arch/x86/kvm/emulate.c b/arch/x86/kvm/emulate.c
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index eb3b1c46f995..97da5034d812 100644
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--- a/arch/x86/kvm/emulate.c
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+++ b/arch/x86/kvm/emulate.c
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@@ -3462,6 +3462,12 @@ static int em_bswap(struct x86_emulate_ctxt *ctxt)
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return X86EMUL_CONTINUE;
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}
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+static int em_clflush(struct x86_emulate_ctxt *ctxt)
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+{
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+ /* emulating clflush regardless of cpuid */
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+ return X86EMUL_CONTINUE;
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+}
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+
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static bool valid_cr(int nr)
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{
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switch (nr) {
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@@ -3800,6 +3806,16 @@ static const struct opcode group11[] = {
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X7(D(Undefined)),
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};
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+static const struct gprefix pfx_0f_ae_7 = {
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+ I(0, em_clflush), N, N, N,
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+};
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+
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+static const struct group_dual group15 = { {
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+ N, N, N, N, N, N, N, GP(0, &pfx_0f_ae_7),
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+}, {
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+ N, N, N, N, N, N, N, N,
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+} };
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+
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static const struct gprefix pfx_0f_6f_0f_7f = {
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I(Mmx, em_mov), I(Sse | Aligned, em_mov), N, I(Sse | Unaligned, em_mov),
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};
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@@ -4063,7 +4079,7 @@ static const struct opcode twobyte_table[256] = {
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F(DstMem | SrcReg | ModRM | BitOp | Lock | PageTable, em_bts),
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F(DstMem | SrcReg | Src2ImmByte | ModRM, em_shrd),
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F(DstMem | SrcReg | Src2CL | ModRM, em_shrd),
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- D(ModRM), F(DstReg | SrcMem | ModRM, em_imul),
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+ GD(0, &group15), F(DstReg | SrcMem | ModRM, em_imul),
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/* 0xB0 - 0xB7 */
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I2bv(DstMem | SrcReg | ModRM | Lock | PageTable, em_cmpxchg),
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I(DstReg | SrcMemFAddr | ModRM | Src2SS, em_lseg),
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@@ -4993,8 +5009,6 @@ twobyte_insn:
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case 0x90 ... 0x9f: /* setcc r/m8 */
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ctxt->dst.val = test_cc(ctxt->b, ctxt->eflags);
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break;
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- case 0xae: /* clflush */
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- break;
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case 0xb6 ... 0xb7: /* movzx */
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ctxt->dst.bytes = ctxt->op_bytes;
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ctxt->dst.val = (ctxt->src.bytes == 1) ? (u8) ctxt->src.val
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--
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1.9.3
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