| Message ID | 20150302210202.2951.56810.stgit@joelvmguard2.amd.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
2015-03-02 15:02-0600, Joel Schopp: > +int kvm_fast_pio_in(struct kvm_vcpu *vcpu, int size, unsigned short port) > +{ > + unsigned long val; > + int ret = emulator_pio_in_emulated(&vcpu->arch.emulate_ctxt, size, > + port, &val, 1); > + Btw. does this return 1 in some scenario? > + if (ret) > + kvm_register_write(vcpu, VCPU_REGS_RAX, val); > + else > + vcpu->arch.complete_userspace_io = complete_fast_pio; > + > + return ret; > +} > +EXPORT_SYMBOL_GPL(kvm_fast_pio_in); -- 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 03/03/2015 10:44 AM, Radim Kr?má? wrote: > 2015-03-02 15:02-0600, Joel Schopp: >> +int kvm_fast_pio_in(struct kvm_vcpu *vcpu, int size, unsigned short port) >> +{ >> + unsigned long val; >> + int ret = emulator_pio_in_emulated(&vcpu->arch.emulate_ctxt, size, >> + port, &val, 1); >> + > Btw. does this return 1 in some scenario? If a function returns a value it is always a good idea to check it and act appropriately. That said... emulator_pio_in_emulated will return 1 if emulator_pio_in_out returns 1 or if vcpu->arch.pio.count != 0 emulator_pio_in_out returns 1 if kernel_pio returns 0 kernel_pio returns 0 if kvm_io_bus_read returns 0 -- 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
2015-03-03 14:03-0600, Joel Schopp: > On 03/03/2015 10:44 AM, Radim Kr?má? wrote: > > 2015-03-02 15:02-0600, Joel Schopp: > >> + int ret = emulator_pio_in_emulated(&vcpu->arch.emulate_ctxt, size, > >> + port, &val, 1); > > Btw. does this return 1 in some scenario? > If a function returns a value it is always a good idea to check it and > act appropriately. That said... > emulator_pio_in_emulated will return 1 if emulator_pio_in_out returns 1 Ah, I have completely forgotten, 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
On Mon, Mar 02, 2015 at 03:02:02PM -0600, Joel Schopp wrote: > From: David Kaplan <David.Kaplan@amd.com> > > We can make the in instruction go faster the same way the out instruction is > already. > > Changes from v2[Joel]: > * changed rax from u32 to unsigned long > * changed a couple return 0 to BUG_ON() > * changed 8 to sizeof(new_rax) > * added trace hook > * removed redundant clearing of count > Changes from v1[Joel] > * Added kvm_fast_pio_in() implementation that was left out of v1 > > Signed-off-by: David Kaplan <David.Kaplan@amd.com> > [extracted from larger unlrelated patch, forward ported, addressed reviews, tested] > Signed-off-by: Joel Schopp <joel.schopp@amd.com> > --- > arch/x86/include/asm/kvm_host.h | 1 + > arch/x86/kvm/svm.c | 4 +++- > arch/x86/kvm/x86.c | 30 ++++++++++++++++++++++++++++++ > 3 files changed, 34 insertions(+), 1 deletion(-) > > diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h > index a236e39..b976824 100644 > --- a/arch/x86/include/asm/kvm_host.h > +++ b/arch/x86/include/asm/kvm_host.h > @@ -931,6 +931,7 @@ int kvm_set_msr(struct kvm_vcpu *vcpu, struct msr_data *msr); > struct x86_emulate_ctxt; > > int kvm_fast_pio_out(struct kvm_vcpu *vcpu, int size, unsigned short port); > +int kvm_fast_pio_in(struct kvm_vcpu *vcpu, int size, unsigned short port); > void kvm_emulate_cpuid(struct kvm_vcpu *vcpu); > int kvm_emulate_halt(struct kvm_vcpu *vcpu); > int kvm_emulate_wbinvd(struct kvm_vcpu *vcpu); > diff --git a/arch/x86/kvm/svm.c b/arch/x86/kvm/svm.c > index d319e0c..f8c906b 100644 > --- a/arch/x86/kvm/svm.c > +++ b/arch/x86/kvm/svm.c > @@ -1899,7 +1899,7 @@ static int io_interception(struct vcpu_svm *svm) > ++svm->vcpu.stat.io_exits; > string = (io_info & SVM_IOIO_STR_MASK) != 0; > in = (io_info & SVM_IOIO_TYPE_MASK) != 0; > - if (string || in) > + if (string) > return emulate_instruction(vcpu, 0) == EMULATE_DONE; > > port = io_info >> 16; > @@ -1907,6 +1907,8 @@ static int io_interception(struct vcpu_svm *svm) > svm->next_rip = svm->vmcb->control.exit_info_2; > skip_emulated_instruction(&svm->vcpu); > > + if (in) > + return kvm_fast_pio_in(vcpu, size, port); > return kvm_fast_pio_out(vcpu, size, port); > } > > diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c > index bd7a70b..d05efaf 100644 > --- a/arch/x86/kvm/x86.c > +++ b/arch/x86/kvm/x86.c > @@ -5463,6 +5463,36 @@ int kvm_fast_pio_out(struct kvm_vcpu *vcpu, int size, unsigned short port) > } > EXPORT_SYMBOL_GPL(kvm_fast_pio_out); > > +static int complete_fast_pio(struct kvm_vcpu *vcpu) > +{ > + unsigned long new_rax = kvm_register_read(vcpu, VCPU_REGS_RAX); > + > + BUG_ON(!vcpu->arch.pio.count); > + BUG_ON(vcpu->arch.pio.count * vcpu->arch.pio.size > sizeof(new_rax)); > + > + memcpy(&new_rax, vcpu, sizeof(new_rax)); Weird. > + trace_kvm_pio(KVM_PIO_IN, vcpu->arch.pio.port, vcpu->arch.pio.size, > + vcpu->arch.pio.count, vcpu->arch.pio_data); > + kvm_register_write(vcpu, VCPU_REGS_RAX, new_rax); > + vcpu->arch.pio.count = 0; > + return 1; > +} > + > +int kvm_fast_pio_in(struct kvm_vcpu *vcpu, int size, unsigned short port) > +{ > + unsigned long val; Please zero initialize val. Please check sanity of size. -- 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/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h index a236e39..b976824 100644 --- a/arch/x86/include/asm/kvm_host.h +++ b/arch/x86/include/asm/kvm_host.h @@ -931,6 +931,7 @@ int kvm_set_msr(struct kvm_vcpu *vcpu, struct msr_data *msr); struct x86_emulate_ctxt; int kvm_fast_pio_out(struct kvm_vcpu *vcpu, int size, unsigned short port); +int kvm_fast_pio_in(struct kvm_vcpu *vcpu, int size, unsigned short port); void kvm_emulate_cpuid(struct kvm_vcpu *vcpu); int kvm_emulate_halt(struct kvm_vcpu *vcpu); int kvm_emulate_wbinvd(struct kvm_vcpu *vcpu); diff --git a/arch/x86/kvm/svm.c b/arch/x86/kvm/svm.c index d319e0c..f8c906b 100644 --- a/arch/x86/kvm/svm.c +++ b/arch/x86/kvm/svm.c @@ -1899,7 +1899,7 @@ static int io_interception(struct vcpu_svm *svm) ++svm->vcpu.stat.io_exits; string = (io_info & SVM_IOIO_STR_MASK) != 0; in = (io_info & SVM_IOIO_TYPE_MASK) != 0; - if (string || in) + if (string) return emulate_instruction(vcpu, 0) == EMULATE_DONE; port = io_info >> 16; @@ -1907,6 +1907,8 @@ static int io_interception(struct vcpu_svm *svm) svm->next_rip = svm->vmcb->control.exit_info_2; skip_emulated_instruction(&svm->vcpu); + if (in) + return kvm_fast_pio_in(vcpu, size, port); return kvm_fast_pio_out(vcpu, size, port); } diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index bd7a70b..d05efaf 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -5463,6 +5463,36 @@ int kvm_fast_pio_out(struct kvm_vcpu *vcpu, int size, unsigned short port) } EXPORT_SYMBOL_GPL(kvm_fast_pio_out); +static int complete_fast_pio(struct kvm_vcpu *vcpu) +{ + unsigned long new_rax = kvm_register_read(vcpu, VCPU_REGS_RAX); + + BUG_ON(!vcpu->arch.pio.count); + BUG_ON(vcpu->arch.pio.count * vcpu->arch.pio.size > sizeof(new_rax)); + + memcpy(&new_rax, vcpu, sizeof(new_rax)); + trace_kvm_pio(KVM_PIO_IN, vcpu->arch.pio.port, vcpu->arch.pio.size, + vcpu->arch.pio.count, vcpu->arch.pio_data); + kvm_register_write(vcpu, VCPU_REGS_RAX, new_rax); + vcpu->arch.pio.count = 0; + return 1; +} + +int kvm_fast_pio_in(struct kvm_vcpu *vcpu, int size, unsigned short port) +{ + unsigned long val; + int ret = emulator_pio_in_emulated(&vcpu->arch.emulate_ctxt, size, + port, &val, 1); + + if (ret) + kvm_register_write(vcpu, VCPU_REGS_RAX, val); + else + vcpu->arch.complete_userspace_io = complete_fast_pio; + + return ret; +} +EXPORT_SYMBOL_GPL(kvm_fast_pio_in); + static void tsc_bad(void *info) { __this_cpu_write(cpu_tsc_khz, 0);