| Message ID | 1573289934-14430-1-git-send-email-linmiaohe@huawei.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | KVM: X86: avoid unused setup_syscalls_segments call when SYSCALL check failed | expand |
On 09/11/19 09:58, linmiaohe wrote: > From: Miaohe Lin <linmiaohe@huawei.com> > > When SYSCALL/SYSENTER ability check failed, cs and ss is inited but > remain not used. Delay initializing cs and ss until SYSCALL/SYSENTER > ability check passed. > > Signed-off-by: Miaohe Lin <linmiaohe@huawei.com> > --- > arch/x86/kvm/emulate.c | 6 ++---- > 1 file changed, 2 insertions(+), 4 deletions(-) > > diff --git a/arch/x86/kvm/emulate.c b/arch/x86/kvm/emulate.c > index 698efb8c3897..952d1a4f4d7e 100644 > --- a/arch/x86/kvm/emulate.c > +++ b/arch/x86/kvm/emulate.c > @@ -2770,11 +2770,10 @@ static int em_syscall(struct x86_emulate_ctxt *ctxt) > return emulate_ud(ctxt); > > ops->get_msr(ctxt, MSR_EFER, &efer); > - setup_syscalls_segments(ctxt, &cs, &ss); > - > if (!(efer & EFER_SCE)) > return emulate_ud(ctxt); > > + setup_syscalls_segments(ctxt, &cs, &ss); > ops->get_msr(ctxt, MSR_STAR, &msr_data); > msr_data >>= 32; > cs_sel = (u16)(msr_data & 0xfffc); > @@ -2838,12 +2837,11 @@ static int em_sysenter(struct x86_emulate_ctxt *ctxt) > if (ctxt->mode == X86EMUL_MODE_PROT64) > return X86EMUL_UNHANDLEABLE; > > - setup_syscalls_segments(ctxt, &cs, &ss); > - > ops->get_msr(ctxt, MSR_IA32_SYSENTER_CS, &msr_data); > if ((msr_data & 0xfffc) == 0x0) > return emulate_gp(ctxt, 0); > > + setup_syscalls_segments(ctxt, &cs, &ss); > ctxt->eflags &= ~(X86_EFLAGS_VM | X86_EFLAGS_IF); > cs_sel = (u16)msr_data & ~SEGMENT_RPL_MASK; > ss_sel = cs_sel + 8; > Queued, thanks. Paolo
diff --git a/arch/x86/kvm/emulate.c b/arch/x86/kvm/emulate.c index 698efb8c3897..952d1a4f4d7e 100644 --- a/arch/x86/kvm/emulate.c +++ b/arch/x86/kvm/emulate.c @@ -2770,11 +2770,10 @@ static int em_syscall(struct x86_emulate_ctxt *ctxt) return emulate_ud(ctxt); ops->get_msr(ctxt, MSR_EFER, &efer); - setup_syscalls_segments(ctxt, &cs, &ss); - if (!(efer & EFER_SCE)) return emulate_ud(ctxt); + setup_syscalls_segments(ctxt, &cs, &ss); ops->get_msr(ctxt, MSR_STAR, &msr_data); msr_data >>= 32; cs_sel = (u16)(msr_data & 0xfffc); @@ -2838,12 +2837,11 @@ static int em_sysenter(struct x86_emulate_ctxt *ctxt) if (ctxt->mode == X86EMUL_MODE_PROT64) return X86EMUL_UNHANDLEABLE; - setup_syscalls_segments(ctxt, &cs, &ss); - ops->get_msr(ctxt, MSR_IA32_SYSENTER_CS, &msr_data); if ((msr_data & 0xfffc) == 0x0) return emulate_gp(ctxt, 0); + setup_syscalls_segments(ctxt, &cs, &ss); ctxt->eflags &= ~(X86_EFLAGS_VM | X86_EFLAGS_IF); cs_sel = (u16)msr_data & ~SEGMENT_RPL_MASK; ss_sel = cs_sel + 8;