* [PATCH v3 0/3] Vendor specific instructions and the emulator
@ 2011-02-01 14:32 Avi Kivity
2011-02-01 14:32 ` [PATCH v3 1/3] KVM: Drop bogus x86_decode_insn() error check Avi Kivity
` (3 more replies)
0 siblings, 4 replies; 5+ messages in thread
From: Avi Kivity @ 2011-02-01 14:32 UTC (permalink / raw)
To: Marcelo Tosatti, kvm
Currently we have some ad-hoc code in x86.c to restrict #UD emulation to
expected instructions (that is, vendor specific instructions). This patchset
replaces the ad-hoc code with proper emulator support using decode tables.
Avi Kivity (3):
KVM: Drop bogus x86_decode_insn() error check
v2: replaces v1's first two patches
KVM: x86 emulator: vendor specific instructions
KVM: Drop ad-hoc vendor specific instruction restriction
v3: preserve early-exit on #UD (reexecute_instruction() isn't reliable
since we don't have a valid cr2)
arch/x86/include/asm/kvm_emulate.h | 1 +
arch/x86/kvm/emulate.c | 12 +++++++++---
arch/x86/kvm/x86.c | 36 +++++-------------------------------
3 files changed, 15 insertions(+), 34 deletions(-)
^ permalink raw reply [flat|nested] 5+ messages in thread* [PATCH v3 1/3] KVM: Drop bogus x86_decode_insn() error check 2011-02-01 14:32 [PATCH v3 0/3] Vendor specific instructions and the emulator Avi Kivity @ 2011-02-01 14:32 ` Avi Kivity 2011-02-01 14:32 ` [PATCH v3 2/3] KVM: x86 emulator: vendor specific instructions Avi Kivity ` (2 subsequent siblings) 3 siblings, 0 replies; 5+ messages in thread From: Avi Kivity @ 2011-02-01 14:32 UTC (permalink / raw) To: Marcelo Tosatti, kvm x86_decode_insn() doesn't return X86EMUL_* values, so the check for X86EMUL_PROPOGATE_FAULT will always fail. There is a proper check later on, so there is no need for a replacement for this code. Signed-off-by: Avi Kivity <avi@redhat.com> --- arch/x86/kvm/x86.c | 3 --- 1 files changed, 0 insertions(+), 3 deletions(-) diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index a7f65aa..803604f 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -4388,8 +4388,6 @@ int x86_emulate_instruction(struct kvm_vcpu *vcpu, vcpu->arch.emulate_ctxt.perm_ok = false; r = x86_decode_insn(&vcpu->arch.emulate_ctxt, insn, insn_len); - if (r == X86EMUL_PROPAGATE_FAULT) - goto done; trace_kvm_emulate_insn_start(vcpu); @@ -4449,7 +4447,6 @@ restart: return handle_emulation_failure(vcpu); } -done: if (vcpu->arch.emulate_ctxt.have_exception) { inject_emulated_exception(vcpu); r = EMULATE_DONE; -- 1.7.1 ^ permalink raw reply related [flat|nested] 5+ messages in thread
* [PATCH v3 2/3] KVM: x86 emulator: vendor specific instructions 2011-02-01 14:32 [PATCH v3 0/3] Vendor specific instructions and the emulator Avi Kivity 2011-02-01 14:32 ` [PATCH v3 1/3] KVM: Drop bogus x86_decode_insn() error check Avi Kivity @ 2011-02-01 14:32 ` Avi Kivity 2011-02-01 14:32 ` [PATCH v3 3/3] KVM: Drop ad-hoc vendor specific instruction restriction Avi Kivity 2011-02-04 13:25 ` [PATCH v3 0/3] Vendor specific instructions and the emulator Marcelo Tosatti 3 siblings, 0 replies; 5+ messages in thread From: Avi Kivity @ 2011-02-01 14:32 UTC (permalink / raw) To: Marcelo Tosatti, kvm Mark some instructions as vendor specific, and allow the caller to request emulation only of vendor specific instructions. This is useful in some circumstances (responding to a #UD fault). Signed-off-by: Avi Kivity <avi@redhat.com> --- arch/x86/include/asm/kvm_emulate.h | 1 + arch/x86/kvm/emulate.c | 12 +++++++++--- 2 files changed, 10 insertions(+), 3 deletions(-) diff --git a/arch/x86/include/asm/kvm_emulate.h b/arch/x86/include/asm/kvm_emulate.h index 8e37deb..50ebc32 100644 --- a/arch/x86/include/asm/kvm_emulate.h +++ b/arch/x86/include/asm/kvm_emulate.h @@ -239,6 +239,7 @@ struct x86_emulate_ctxt { int interruptibility; bool perm_ok; /* do not check permissions if true */ + bool only_vendor_specific_insn; bool have_exception; struct x86_exception exception; diff --git a/arch/x86/kvm/emulate.c b/arch/x86/kvm/emulate.c index 02a0041..ad46239 100644 --- a/arch/x86/kvm/emulate.c +++ b/arch/x86/kvm/emulate.c @@ -76,6 +76,7 @@ #define Group (1<<14) /* Bits 3:5 of modrm byte extend opcode */ #define GroupDual (1<<15) /* Alternate decoding of mod == 3 */ /* Misc flags */ +#define VendorSpecific (1<<22) /* Vendor specific instruction */ #define NoAccess (1<<23) /* Don't access memory (lea/invlpg/verr etc) */ #define Op3264 (1<<24) /* Operand is 64b in long mode, 32b otherwise */ #define Undefined (1<<25) /* No Such Instruction */ @@ -2365,7 +2366,8 @@ static struct group_dual group7 = { { D(SrcMem16 | ModRM | Mov | Priv), D(SrcMem | ModRM | ByteOp | Priv | NoAccess), }, { - D(SrcNone | ModRM | Priv), N, N, D(SrcNone | ModRM | Priv), + D(SrcNone | ModRM | Priv | VendorSpecific), N, + N, D(SrcNone | ModRM | Priv | VendorSpecific), D(SrcNone | ModRM | DstMem | Mov), N, D(SrcMem16 | ModRM | Mov | Priv), N, } }; @@ -2489,7 +2491,7 @@ static struct opcode opcode_table[256] = { static struct opcode twobyte_table[256] = { /* 0x00 - 0x0F */ N, GD(0, &group7), N, N, - N, D(ImplicitOps), D(ImplicitOps | Priv), N, + N, D(ImplicitOps | VendorSpecific), D(ImplicitOps | Priv), N, D(ImplicitOps | Priv), D(ImplicitOps | Priv), N, N, N, D(ImplicitOps | ModRM), N, N, /* 0x10 - 0x1F */ @@ -2502,7 +2504,8 @@ static struct opcode twobyte_table[256] = { /* 0x30 - 0x3F */ D(ImplicitOps | Priv), I(ImplicitOps, em_rdtsc), D(ImplicitOps | Priv), N, - D(ImplicitOps), D(ImplicitOps | Priv), N, N, + D(ImplicitOps | VendorSpecific), D(ImplicitOps | Priv | VendorSpecific), + N, N, N, N, N, N, N, N, N, N, /* 0x40 - 0x4F */ X16(D(DstReg | SrcMem | ModRM | Mov)), @@ -2741,6 +2744,9 @@ done_prefixes: if (c->d == 0 || (c->d & Undefined)) return -1; + if (!(c->d & VendorSpecific) && ctxt->only_vendor_specific_insn) + return -1; + if (mode == X86EMUL_MODE_PROT64 && (c->d & Stack)) c->op_bytes = 8; -- 1.7.1 ^ permalink raw reply related [flat|nested] 5+ messages in thread
* [PATCH v3 3/3] KVM: Drop ad-hoc vendor specific instruction restriction 2011-02-01 14:32 [PATCH v3 0/3] Vendor specific instructions and the emulator Avi Kivity 2011-02-01 14:32 ` [PATCH v3 1/3] KVM: Drop bogus x86_decode_insn() error check Avi Kivity 2011-02-01 14:32 ` [PATCH v3 2/3] KVM: x86 emulator: vendor specific instructions Avi Kivity @ 2011-02-01 14:32 ` Avi Kivity 2011-02-04 13:25 ` [PATCH v3 0/3] Vendor specific instructions and the emulator Marcelo Tosatti 3 siblings, 0 replies; 5+ messages in thread From: Avi Kivity @ 2011-02-01 14:32 UTC (permalink / raw) To: Marcelo Tosatti, kvm Use the new support in the emulator, and drop the ad-hoc code in x86.c. Signed-off-by: Avi Kivity <avi@redhat.com> --- arch/x86/kvm/x86.c | 33 +++++---------------------------- 1 files changed, 5 insertions(+), 28 deletions(-) diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index 803604f..bdbe2e8 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -4387,39 +4387,16 @@ int x86_emulate_instruction(struct kvm_vcpu *vcpu, vcpu->arch.emulate_ctxt.have_exception = false; vcpu->arch.emulate_ctxt.perm_ok = false; + vcpu->arch.emulate_ctxt.only_vendor_specific_insn + = emulation_type & EMULTYPE_TRAP_UD; + r = x86_decode_insn(&vcpu->arch.emulate_ctxt, insn, insn_len); trace_kvm_emulate_insn_start(vcpu); - - /* Only allow emulation of specific instructions on #UD - * (namely VMMCALL, sysenter, sysexit, syscall)*/ - if (emulation_type & EMULTYPE_TRAP_UD) { - if (!c->twobyte) - return EMULATE_FAIL; - switch (c->b) { - case 0x01: /* VMMCALL */ - if (c->modrm_mod != 3 || c->modrm_rm != 1) - return EMULATE_FAIL; - break; - case 0x34: /* sysenter */ - case 0x35: /* sysexit */ - if (c->modrm_mod != 0 || c->modrm_rm != 0) - return EMULATE_FAIL; - break; - case 0x05: /* syscall */ - if (c->modrm_mod != 0 || c->modrm_rm != 0) - return EMULATE_FAIL; - break; - default: - return EMULATE_FAIL; - } - - if (!(c->modrm_reg == 0 || c->modrm_reg == 3)) - return EMULATE_FAIL; - } - ++vcpu->stat.insn_emulation; if (r) { + if (emulation_type & EMULTYPE_TRAP_UD) + return EMULATE_FAIL; if (reexecute_instruction(vcpu, cr2)) return EMULATE_DONE; if (emulation_type & EMULTYPE_SKIP) -- 1.7.1 ^ permalink raw reply related [flat|nested] 5+ messages in thread
* Re: [PATCH v3 0/3] Vendor specific instructions and the emulator 2011-02-01 14:32 [PATCH v3 0/3] Vendor specific instructions and the emulator Avi Kivity ` (2 preceding siblings ...) 2011-02-01 14:32 ` [PATCH v3 3/3] KVM: Drop ad-hoc vendor specific instruction restriction Avi Kivity @ 2011-02-04 13:25 ` Marcelo Tosatti 3 siblings, 0 replies; 5+ messages in thread From: Marcelo Tosatti @ 2011-02-04 13:25 UTC (permalink / raw) To: Avi Kivity; +Cc: kvm On Tue, Feb 01, 2011 at 04:32:01PM +0200, Avi Kivity wrote: > Currently we have some ad-hoc code in x86.c to restrict #UD emulation to > expected instructions (that is, vendor specific instructions). This patchset > replaces the ad-hoc code with proper emulator support using decode tables. > > Avi Kivity (3): > KVM: Drop bogus x86_decode_insn() error check > v2: replaces v1's first two patches > KVM: x86 emulator: vendor specific instructions > KVM: Drop ad-hoc vendor specific instruction restriction > v3: preserve early-exit on #UD (reexecute_instruction() isn't reliable > since we don't have a valid cr2) > > arch/x86/include/asm/kvm_emulate.h | 1 + > arch/x86/kvm/emulate.c | 12 +++++++++--- > arch/x86/kvm/x86.c | 36 +++++------------------------------- > 3 files changed, 15 insertions(+), 34 deletions(-) Applied, thanks. ^ permalink raw reply [flat|nested] 5+ messages in thread
end of thread, other threads:[~2011-02-04 14:37 UTC | newest] Thread overview: 5+ messages (download: mbox.gz / follow: Atom feed) -- links below jump to the message on this page -- 2011-02-01 14:32 [PATCH v3 0/3] Vendor specific instructions and the emulator Avi Kivity 2011-02-01 14:32 ` [PATCH v3 1/3] KVM: Drop bogus x86_decode_insn() error check Avi Kivity 2011-02-01 14:32 ` [PATCH v3 2/3] KVM: x86 emulator: vendor specific instructions Avi Kivity 2011-02-01 14:32 ` [PATCH v3 3/3] KVM: Drop ad-hoc vendor specific instruction restriction Avi Kivity 2011-02-04 13:25 ` [PATCH v3 0/3] Vendor specific instructions and the emulator Marcelo Tosatti
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