Eric Lee / smarc-ti-linux-kernel

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Commit 13e457e0eebf0a0c82c38ceb890d93eb826d62a6

Authored by Nadav Amit
Committed by Paolo Bonzini
1 parent a430c91663
Exists in ti-lsk-linux-4.1.y and in 10 other branches dlt-processor-sdk-linux-03.00.00.04, processor-sdk-linux-02.00.01, smarc-ti-lsk-linux-4.1.y, smarct3x-processor-sdk-04.01.00.06, smarct3x-processor-sdk-linux-02.00.01, smarct3x-processor-sdk-linux-03.00.00.04, smarct4x-800-processor-sdk-linux-02.00.01, smarct4x-processor-sdk-04.01.00.06, smarct4x-processor-sdk-linux-02.00.01, smarct4x-processor-sdk-linux-03.00.00.04

KVM: x86: Emulator does not decode clflush well 

Currently, all group15 instructions are decoded as clflush (e.g., mfence,
xsave).  In addition, the clflush instruction requires no prefix (66/f2/f3)
would exist. If prefix exists it may encode a different instruction (e.g.,
clflushopt).

Creating a group for clflush, and different group for each prefix.

This has been the case forever, but the next patch needs the cflush group
in order to fix a bug introduced in 3.17.

Fixes: 41061cdb98a0bec464278b4db8e894a3121671f5
Cc: stable@vger.kernel.org
Signed-off-by: Nadav Amit <namit@cs.technion.ac.il>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

Showing 1 changed file with 17 additions and 3 deletions Side-by-side Diff

arch/x86/kvm/emulate.c
Diff comments   View file @ 13e457e
... ... @@ -3462,6 +3462,12 @@
3462 3462 return X86EMUL_CONTINUE;
3463 3463 }
3464 3464  
  3465 +static int em_clflush(struct x86_emulate_ctxt *ctxt)
  3466 +{
  3467 + /* emulating clflush regardless of cpuid */
  3468 + return X86EMUL_CONTINUE;
  3469 +}
  3470 +
3465 3471 static bool valid_cr(int nr)
3466 3472 {
3467 3473 switch (nr) {
... ... @@ -3800,6 +3806,16 @@
3800 3806 X7(D(Undefined)),
3801 3807 };
3802 3808  
  3809 +static const struct gprefix pfx_0f_ae_7 = {
  3810 + I(0, em_clflush), N, N, N,
  3811 +};
  3812 +
  3813 +static const struct group_dual group15 = { {
  3814 + N, N, N, N, N, N, N, GP(0, &pfx_0f_ae_7),
  3815 +}, {
  3816 + N, N, N, N, N, N, N, N,
  3817 +} };
  3818 +
3803 3819 static const struct gprefix pfx_0f_6f_0f_7f = {
3804 3820 I(Mmx, em_mov), I(Sse | Aligned, em_mov), N, I(Sse | Unaligned, em_mov),
3805 3821 };
... ... @@ -4063,7 +4079,7 @@
4063 4079 F(DstMem | SrcReg | ModRM | BitOp | Lock | PageTable, em_bts),
4064 4080 F(DstMem | SrcReg | Src2ImmByte | ModRM, em_shrd),
4065 4081 F(DstMem | SrcReg | Src2CL | ModRM, em_shrd),
4066   - D(ModRM), F(DstReg | SrcMem | ModRM, em_imul),
  4082 + GD(0, &group15), F(DstReg | SrcMem | ModRM, em_imul),
4067 4083 /* 0xB0 - 0xB7 */
4068 4084 I2bv(DstMem | SrcReg | ModRM | Lock | PageTable, em_cmpxchg),
4069 4085 I(DstReg | SrcMemFAddr | ModRM | Src2SS, em_lseg),
... ... @@ -4992,8 +5008,6 @@
4992 5008 break;
4993 5009 case 0x90 ... 0x9f: /* setcc r/m8 */
4994 5010 ctxt->dst.val = test_cc(ctxt->b, ctxt->eflags);
4995   - break;
4996   - case 0xae: /* clflush */
4997 5011 break;
4998 5012 case 0xb6 ... 0xb7: /* movzx */
4999 5013 ctxt->dst.bytes = ctxt->op_bytes;