| Message ID | 1363707026-19351-1-git-send-email-pbonzini@redhat.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On Tue, Mar 19, 2013 at 04:30:26PM +0100, Paolo Bonzini wrote: > The CS base was initialized to 0 on VMX (wrong, but usually overridden > by userspace before starting) or 0xf0000 on SVM. The correct value is > 0xffff0000, and VMX is able to emulate it now, so use it. > > Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Reviewed-by: Gleb Natapov <gleb@redhat.com> > --- > arch/x86/kvm/svm.c | 8 +------- > arch/x86/kvm/vmx.c | 1 + > 2 files changed, 2 insertions(+), 7 deletions(-) > > diff --git a/arch/x86/kvm/svm.c b/arch/x86/kvm/svm.c > index 7219a40..7a46c1f 100644 > --- a/arch/x86/kvm/svm.c > +++ b/arch/x86/kvm/svm.c > @@ -1131,17 +1131,11 @@ static void init_vmcb(struct vcpu_svm *svm) > init_seg(&save->gs); > > save->cs.selector = 0xf000; > + save->cs.base = 0xffff0000; > /* Executable/Readable Code Segment */ > save->cs.attrib = SVM_SELECTOR_READ_MASK | SVM_SELECTOR_P_MASK | > SVM_SELECTOR_S_MASK | SVM_SELECTOR_CODE_MASK; > save->cs.limit = 0xffff; > - /* > - * cs.base should really be 0xffff0000, but vmx can't handle that, so > - * be consistent with it. > - * > - * Replace when we have real mode working for vmx. > - */ > - save->cs.base = 0xf0000; > > save->gdtr.limit = 0xffff; > save->idtr.limit = 0xffff; > diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c > index 4a0bafe..c75c25d 100644 > --- a/arch/x86/kvm/vmx.c > +++ b/arch/x86/kvm/vmx.c > @@ -4133,6 +4133,7 @@ static void vmx_vcpu_reset(struct kvm_vcpu *vcpu) > > seg_setup(VCPU_SREG_CS); > vmcs_write16(GUEST_CS_SELECTOR, 0xf000); > + vmcs_write32(GUEST_CS_BASE, 0xffff0000); > > seg_setup(VCPU_SREG_DS); > seg_setup(VCPU_SREG_ES); > -- > 1.8.1.4 > > -- > To unsubscribe from this list: send the line "unsubscribe kvm" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html -- Gleb. -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On 2013-03-19 16:43, Gleb Natapov wrote: > On Tue, Mar 19, 2013 at 04:30:26PM +0100, Paolo Bonzini wrote: >> The CS base was initialized to 0 on VMX (wrong, but usually overridden >> by userspace before starting) or 0xf0000 on SVM. The correct value is >> 0xffff0000, and VMX is able to emulate it now, so use it. >> >> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> > Reviewed-by: Gleb Natapov <gleb@redhat.com> Just for the history (as I was wondering where this came from): CS base used to be set to 0xf0000 on VMX as well, but that was changed by b246dd5d to only affect guests when unrestricted mode is missing. That change actually left the base uninitialized. Jan > >> --- >> arch/x86/kvm/svm.c | 8 +------- >> arch/x86/kvm/vmx.c | 1 + >> 2 files changed, 2 insertions(+), 7 deletions(-) >> >> diff --git a/arch/x86/kvm/svm.c b/arch/x86/kvm/svm.c >> index 7219a40..7a46c1f 100644 >> --- a/arch/x86/kvm/svm.c >> +++ b/arch/x86/kvm/svm.c >> @@ -1131,17 +1131,11 @@ static void init_vmcb(struct vcpu_svm *svm) >> init_seg(&save->gs); >> >> save->cs.selector = 0xf000; >> + save->cs.base = 0xffff0000; >> /* Executable/Readable Code Segment */ >> save->cs.attrib = SVM_SELECTOR_READ_MASK | SVM_SELECTOR_P_MASK | >> SVM_SELECTOR_S_MASK | SVM_SELECTOR_CODE_MASK; >> save->cs.limit = 0xffff; >> - /* >> - * cs.base should really be 0xffff0000, but vmx can't handle that, so >> - * be consistent with it. >> - * >> - * Replace when we have real mode working for vmx. >> - */ >> - save->cs.base = 0xf0000; >> >> save->gdtr.limit = 0xffff; >> save->idtr.limit = 0xffff; >> diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c >> index 4a0bafe..c75c25d 100644 >> --- a/arch/x86/kvm/vmx.c >> +++ b/arch/x86/kvm/vmx.c >> @@ -4133,6 +4133,7 @@ static void vmx_vcpu_reset(struct kvm_vcpu *vcpu) >> >> seg_setup(VCPU_SREG_CS); >> vmcs_write16(GUEST_CS_SELECTOR, 0xf000); >> + vmcs_write32(GUEST_CS_BASE, 0xffff0000); >> >> seg_setup(VCPU_SREG_DS); >> seg_setup(VCPU_SREG_ES); >> -- >> 1.8.1.4 >> >> -- >> To unsubscribe from this list: send the line "unsubscribe kvm" in >> the body of a message to majordomo@vger.kernel.org >> More majordomo info at http://vger.kernel.org/majordomo-info.html > > -- > Gleb. >
On Tue, Mar 19, 2013 at 05:41:45PM +0100, Jan Kiszka wrote: > On 2013-03-19 16:43, Gleb Natapov wrote: > > On Tue, Mar 19, 2013 at 04:30:26PM +0100, Paolo Bonzini wrote: > >> The CS base was initialized to 0 on VMX (wrong, but usually overridden > >> by userspace before starting) or 0xf0000 on SVM. The correct value is > >> 0xffff0000, and VMX is able to emulate it now, so use it. > >> > >> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> > > Reviewed-by: Gleb Natapov <gleb@redhat.com> > > Just for the history (as I was wondering where this came from): CS base > used to be set to 0xf0000 on VMX as well, but that was changed by > b246dd5d to only affect guests when unrestricted mode is missing. That > change actually left the base uninitialized. > Looking at the code before b246dd5d it sets CS base to 0xf0000 only if it was 0xffff0000. This is the same as with current code: fix_rmode_seg() does it. -- Gleb. -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On Tue, Mar 19, 2013 at 04:30:26PM +0100, Paolo Bonzini wrote: > The CS base was initialized to 0 on VMX (wrong, but usually overridden > by userspace before starting) or 0xf0000 on SVM. The correct value is > 0xffff0000, and VMX is able to emulate it now, so use it. > > Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> > --- > arch/x86/kvm/svm.c | 8 +------- > arch/x86/kvm/vmx.c | 1 + > 2 files changed, 2 insertions(+), 7 deletions(-) Applied, thanks. -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/arch/x86/kvm/svm.c b/arch/x86/kvm/svm.c index 7219a40..7a46c1f 100644 --- a/arch/x86/kvm/svm.c +++ b/arch/x86/kvm/svm.c @@ -1131,17 +1131,11 @@ static void init_vmcb(struct vcpu_svm *svm) init_seg(&save->gs); save->cs.selector = 0xf000; + save->cs.base = 0xffff0000; /* Executable/Readable Code Segment */ save->cs.attrib = SVM_SELECTOR_READ_MASK | SVM_SELECTOR_P_MASK | SVM_SELECTOR_S_MASK | SVM_SELECTOR_CODE_MASK; save->cs.limit = 0xffff; - /* - * cs.base should really be 0xffff0000, but vmx can't handle that, so - * be consistent with it. - * - * Replace when we have real mode working for vmx. - */ - save->cs.base = 0xf0000; save->gdtr.limit = 0xffff; save->idtr.limit = 0xffff; diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c index 4a0bafe..c75c25d 100644 --- a/arch/x86/kvm/vmx.c +++ b/arch/x86/kvm/vmx.c @@ -4133,6 +4133,7 @@ static void vmx_vcpu_reset(struct kvm_vcpu *vcpu) seg_setup(VCPU_SREG_CS); vmcs_write16(GUEST_CS_SELECTOR, 0xf000); + vmcs_write32(GUEST_CS_BASE, 0xffff0000); seg_setup(VCPU_SREG_DS); seg_setup(VCPU_SREG_ES);
The CS base was initialized to 0 on VMX (wrong, but usually overridden by userspace before starting) or 0xf0000 on SVM. The correct value is 0xffff0000, and VMX is able to emulate it now, so use it. Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> --- arch/x86/kvm/svm.c | 8 +------- arch/x86/kvm/vmx.c | 1 + 2 files changed, 2 insertions(+), 7 deletions(-)