| Message ID | 4E01FC5B.9040809@cn.fujitsu.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On 06/22/2011 05:29 PM, Xiao Guangrong wrote: > Introduce vcpu_gva_to_gpa to translate the gva to gpa, we can use it > to cleanup the code between read emulation and write emulation > > Signed-off-by: Xiao Guangrong<xiaoguangrong@cn.fujitsu.com> > --- > arch/x86/kvm/x86.c | 38 +++++++++++++++++++++++++++++--------- > 1 files changed, 29 insertions(+), 9 deletions(-) > > diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c > index eb27be4..c29ef96 100644 > --- a/arch/x86/kvm/x86.c > +++ b/arch/x86/kvm/x86.c > @@ -3944,6 +3944,27 @@ out: > } > EXPORT_SYMBOL_GPL(kvm_write_guest_virt_system); > > +static int vcpu_gva_to_gpa(struct kvm_vcpu *vcpu, unsigned long gva, > + gpa_t *gpa, struct x86_exception *exception, > + bool write) > +{ > + u32 access = (kvm_x86_ops->get_cpl(vcpu) == 3) ? PFERR_USER_MASK : 0; > + > + if (write) > + access |= PFERR_WRITE_MASK; Needs fetch as well so NX/SMEP can work. > + > + *gpa = vcpu->arch.walk_mmu->gva_to_gpa(vcpu, gva, access, exception);
On 06/29/2011 04:24 PM, Avi Kivity wrote: >> +static int vcpu_gva_to_gpa(struct kvm_vcpu *vcpu, unsigned long gva, >> + gpa_t *gpa, struct x86_exception *exception, >> + bool write) >> +{ >> + u32 access = (kvm_x86_ops->get_cpl(vcpu) == 3) ? PFERR_USER_MASK : 0; >> + >> + if (write) >> + access |= PFERR_WRITE_MASK; > > Needs fetch as well so NX/SMEP can work. > This function is only used by read/write emulator, execute permission is not needed for read/write, no? -- 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 06/29/2011 01:56 PM, Xiao Guangrong wrote: > On 06/29/2011 04:24 PM, Avi Kivity wrote: > > >> +static int vcpu_gva_to_gpa(struct kvm_vcpu *vcpu, unsigned long gva, > >> + gpa_t *gpa, struct x86_exception *exception, > >> + bool write) > >> +{ > >> + u32 access = (kvm_x86_ops->get_cpl(vcpu) == 3) ? PFERR_USER_MASK : 0; > >> + > >> + if (write) > >> + access |= PFERR_WRITE_MASK; > > > > Needs fetch as well so NX/SMEP can work. > > > > This function is only used by read/write emulator, execute permission is > not needed for read/write, no? It's not good to have a function which only implements the functionality partially. It can later be misused. You can pass the page-fault-error-code instead of the write parameter, I think it will be simpler.
On 06/29/2011 07:09 PM, Avi Kivity wrote: > On 06/29/2011 01:56 PM, Xiao Guangrong wrote: >> On 06/29/2011 04:24 PM, Avi Kivity wrote: >> >> >> +static int vcpu_gva_to_gpa(struct kvm_vcpu *vcpu, unsigned long gva, >> >> + gpa_t *gpa, struct x86_exception *exception, >> >> + bool write) >> >> +{ >> >> + u32 access = (kvm_x86_ops->get_cpl(vcpu) == 3) ? PFERR_USER_MASK : 0; >> >> + >> >> + if (write) >> >> + access |= PFERR_WRITE_MASK; >> > >> > Needs fetch as well so NX/SMEP can work. >> > >> >> This function is only used by read/write emulator, execute permission is >> not needed for read/write, no? > > It's not good to have a function which only implements the functionality partially. It can later be misused. > > You can pass the page-fault-error-code instead of the write parameter, I think it will be simpler. > Actually, we will get the cache mmio info in this function, i think it is pure waste for other access execpt mmio, what about change the function name to vcpu_gva_to_gpa_mmio? -- 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 06/29/2011 02:26 PM, Xiao Guangrong wrote: > On 06/29/2011 07:09 PM, Avi Kivity wrote: > > On 06/29/2011 01:56 PM, Xiao Guangrong wrote: > >> On 06/29/2011 04:24 PM, Avi Kivity wrote: > >> > >> >> +static int vcpu_gva_to_gpa(struct kvm_vcpu *vcpu, unsigned long gva, > >> >> + gpa_t *gpa, struct x86_exception *exception, > >> >> + bool write) > >> >> +{ > >> >> + u32 access = (kvm_x86_ops->get_cpl(vcpu) == 3) ? PFERR_USER_MASK : 0; > >> >> + > >> >> + if (write) > >> >> + access |= PFERR_WRITE_MASK; > >> > > >> > Needs fetch as well so NX/SMEP can work. > >> > > >> > >> This function is only used by read/write emulator, execute permission is > >> not needed for read/write, no? > > > > It's not good to have a function which only implements the functionality partially. It can later be misused. > > > > You can pass the page-fault-error-code instead of the write parameter, I think it will be simpler. > > > > Actually, we will get the cache mmio info in this function, i think it is pure waste for other > access execpt mmio, what about change the function name to vcpu_gva_to_gpa_mmio? Not too happy, but ok.
On Wed, Jun 29, 2011 at 02:26:14PM +0300, Avi Kivity wrote: > On 06/29/2011 02:26 PM, Xiao Guangrong wrote: > >On 06/29/2011 07:09 PM, Avi Kivity wrote: > >> On 06/29/2011 01:56 PM, Xiao Guangrong wrote: > >>> On 06/29/2011 04:24 PM, Avi Kivity wrote: > >>> > >>> >> +static int vcpu_gva_to_gpa(struct kvm_vcpu *vcpu, unsigned long gva, > >>> >> + gpa_t *gpa, struct x86_exception *exception, > >>> >> + bool write) > >>> >> +{ > >>> >> + u32 access = (kvm_x86_ops->get_cpl(vcpu) == 3) ? PFERR_USER_MASK : 0; > >>> >> + > >>> >> + if (write) > >>> >> + access |= PFERR_WRITE_MASK; > >>> > > >>> > Needs fetch as well so NX/SMEP can work. > >>> > > >>> > >>> This function is only used by read/write emulator, execute permission is > >>> not needed for read/write, no? > >> > >> It's not good to have a function which only implements the functionality partially. It can later be misused. > >> > >> You can pass the page-fault-error-code instead of the write parameter, I think it will be simpler. > >> > > > >Actually, we will get the cache mmio info in this function, i think it is pure waste for other > >access execpt mmio, what about change the function name to vcpu_gva_to_gpa_mmio? > > Not too happy, but ok. > I do plan to add fetching from MMIO. -- 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
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index eb27be4..c29ef96 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -3944,6 +3944,27 @@ out: } EXPORT_SYMBOL_GPL(kvm_write_guest_virt_system); +static int vcpu_gva_to_gpa(struct kvm_vcpu *vcpu, unsigned long gva, + gpa_t *gpa, struct x86_exception *exception, + bool write) +{ + u32 access = (kvm_x86_ops->get_cpl(vcpu) == 3) ? PFERR_USER_MASK : 0; + + if (write) + access |= PFERR_WRITE_MASK; + + *gpa = vcpu->arch.walk_mmu->gva_to_gpa(vcpu, gva, access, exception); + + if (*gpa == UNMAPPED_GVA) + return -1; + + /* For APIC access vmexit */ + if ((*gpa & PAGE_MASK) == APIC_DEFAULT_PHYS_BASE) + return 1; + + return 0; +} + static int emulator_read_emulated_onepage(unsigned long addr, void *val, unsigned int bytes, @@ -3951,7 +3972,7 @@ static int emulator_read_emulated_onepage(unsigned long addr, struct kvm_vcpu *vcpu) { gpa_t gpa; - int handled; + int handled, ret; if (vcpu->mmio_read_completed) { memcpy(val, vcpu->mmio_data, bytes); @@ -3961,13 +3982,12 @@ static int emulator_read_emulated_onepage(unsigned long addr, return X86EMUL_CONTINUE; } - gpa = kvm_mmu_gva_to_gpa_read(vcpu, addr, exception); + ret = vcpu_gva_to_gpa(vcpu, addr, &gpa, exception, false); - if (gpa == UNMAPPED_GVA) + if (ret < 0) return X86EMUL_PROPAGATE_FAULT; - /* For APIC access vmexit */ - if ((gpa & PAGE_MASK) == APIC_DEFAULT_PHYS_BASE) + if (ret) goto mmio; if (!kvm_read_guest(vcpu->kvm, gpa, val, bytes)) @@ -4043,15 +4063,15 @@ static int emulator_write_emulated_onepage(unsigned long addr, struct kvm_vcpu *vcpu) { gpa_t gpa; - int handled; + int handled, ret; - gpa = kvm_mmu_gva_to_gpa_write(vcpu, addr, exception); + ret = vcpu_gva_to_gpa(vcpu, addr, &gpa, exception, true); - if (gpa == UNMAPPED_GVA) + if (ret < 0) return X86EMUL_PROPAGATE_FAULT; /* For APIC access vmexit */ - if ((gpa & PAGE_MASK) == APIC_DEFAULT_PHYS_BASE) + if (ret) goto mmio; if (emulator_write_phys(vcpu, gpa, val, bytes))
Introduce vcpu_gva_to_gpa to translate the gva to gpa, we can use it to cleanup the code between read emulation and write emulation Signed-off-by: Xiao Guangrong <xiaoguangrong@cn.fujitsu.com> --- arch/x86/kvm/x86.c | 38 +++++++++++++++++++++++++++++--------- 1 files changed, 29 insertions(+), 9 deletions(-)