| Message ID | 20171103225819.GA3482@embeddedor.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
----- Original Message ----- > From: "Gustavo A. R. Silva" <garsilva@embeddedor.com> > To: "Paolo Bonzini" <pbonzini@redhat.com>, "Radim Krčmář" <rkrcmar@redhat.com>, "Thomas Gleixner" > <tglx@linutronix.de>, "Ingo Molnar" <mingo@redhat.com>, "H. Peter Anvin" <hpa@zytor.com>, x86@kernel.org > Cc: kvm@vger.kernel.org, linux-kernel@vger.kernel.org, "Gustavo A. R. Silva" <garsilva@embeddedor.com> > Sent: Friday, November 3, 2017 11:58:19 PM > Subject: [PATCH] KVM: VMX: replace move_msr_up with swap macro > > Function move_msr_up is used to _manually_ swap MSR entries in MSR array. > This function can be removed and replaced using the swap macro instead. > > This code was detected with the help of Coccinelle. I think move_msr_up should instead change into a function like void mark_msr_for_save(struct vcpu_vmx *vmx, int index) { swap(vmx->guest_msrs[index], vmx->guest_msrs[vmx->save_nmsrs]); vmx->save_nmsrs++; } Using swap is useful, but it is also hiding what's going on exactly (in addition, using ++ inside a macro argument might be calling for trouble). Paolo > > Signed-off-by: Gustavo A. R. Silva <garsilva@embeddedor.com> > --- > The new lines are over 80 characters, but I think in this case that is > preferable over splitting them. > > arch/x86/kvm/vmx.c | 24 ++++++------------------ > 1 file changed, 6 insertions(+), 18 deletions(-) > > diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c > index e6c8ffa..210e491 100644 > --- a/arch/x86/kvm/vmx.c > +++ b/arch/x86/kvm/vmx.c > @@ -2544,18 +2544,6 @@ static bool vmx_invpcid_supported(void) > return cpu_has_vmx_invpcid() && enable_ept; > } > > -/* > - * Swap MSR entry in host/guest MSR entry array. > - */ > -static void move_msr_up(struct vcpu_vmx *vmx, int from, int to) > -{ > - struct shared_msr_entry tmp; > - > - tmp = vmx->guest_msrs[to]; > - vmx->guest_msrs[to] = vmx->guest_msrs[from]; > - vmx->guest_msrs[from] = tmp; > -} > - > static void vmx_set_msr_bitmap(struct kvm_vcpu *vcpu) > { > unsigned long *msr_bitmap; > @@ -2600,28 +2588,28 @@ static void setup_msrs(struct vcpu_vmx *vmx) > if (is_long_mode(&vmx->vcpu)) { > index = __find_msr_index(vmx, MSR_SYSCALL_MASK); > if (index >= 0) > - move_msr_up(vmx, index, save_nmsrs++); > + swap(vmx->guest_msrs[index], vmx->guest_msrs[save_nmsrs++]); > index = __find_msr_index(vmx, MSR_LSTAR); > if (index >= 0) > - move_msr_up(vmx, index, save_nmsrs++); > + swap(vmx->guest_msrs[index], vmx->guest_msrs[save_nmsrs++]); > index = __find_msr_index(vmx, MSR_CSTAR); > if (index >= 0) > - move_msr_up(vmx, index, save_nmsrs++); > + swap(vmx->guest_msrs[index], vmx->guest_msrs[save_nmsrs++]); > index = __find_msr_index(vmx, MSR_TSC_AUX); > if (index >= 0 && guest_cpuid_has(&vmx->vcpu, X86_FEATURE_RDTSCP)) > - move_msr_up(vmx, index, save_nmsrs++); > + swap(vmx->guest_msrs[index], vmx->guest_msrs[save_nmsrs++]); > /* > * MSR_STAR is only needed on long mode guests, and only > * if efer.sce is enabled. > */ > index = __find_msr_index(vmx, MSR_STAR); > if ((index >= 0) && (vmx->vcpu.arch.efer & EFER_SCE)) > - move_msr_up(vmx, index, save_nmsrs++); > + swap(vmx->guest_msrs[index], vmx->guest_msrs[save_nmsrs++]); > } > #endif > index = __find_msr_index(vmx, MSR_EFER); > if (index >= 0 && update_transition_efer(vmx, index)) > - move_msr_up(vmx, index, save_nmsrs++); > + swap(vmx->guest_msrs[index], vmx->guest_msrs[save_nmsrs++]); > > vmx->save_nmsrs = save_nmsrs; > > -- > 2.7.4 > >
Hi Paolo, Quoting Paolo Bonzini <pbonzini@redhat.com>: > ----- Original Message ----- >> From: "Gustavo A. R. Silva" <garsilva@embeddedor.com> >> To: "Paolo Bonzini" <pbonzini@redhat.com>, "Radim Krčmář" >> <rkrcmar@redhat.com>, "Thomas Gleixner" >> <tglx@linutronix.de>, "Ingo Molnar" <mingo@redhat.com>, "H. Peter >> Anvin" <hpa@zytor.com>, x86@kernel.org >> Cc: kvm@vger.kernel.org, linux-kernel@vger.kernel.org, "Gustavo A. >> R. Silva" <garsilva@embeddedor.com> >> Sent: Friday, November 3, 2017 11:58:19 PM >> Subject: [PATCH] KVM: VMX: replace move_msr_up with swap macro >> >> Function move_msr_up is used to _manually_ swap MSR entries in MSR array. >> This function can be removed and replaced using the swap macro instead. >> >> This code was detected with the help of Coccinelle. > > I think move_msr_up should instead change into a function like > > void mark_msr_for_save(struct vcpu_vmx *vmx, int index) > { > swap(vmx->guest_msrs[index], vmx->guest_msrs[vmx->save_nmsrs]); > vmx->save_nmsrs++; > } > > Using swap is useful, but it is also hiding what's going on exactly > (in addition, using ++ inside a macro argument might be calling for > trouble). > Thanks for your comments. I'll work on v2 based on your feedback. -- Gustavo A. R. Silva > Paolo > >> >> Signed-off-by: Gustavo A. R. Silva <garsilva@embeddedor.com> >> --- >> The new lines are over 80 characters, but I think in this case that is >> preferable over splitting them. >> >> arch/x86/kvm/vmx.c | 24 ++++++------------------ >> 1 file changed, 6 insertions(+), 18 deletions(-) >> >> diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c >> index e6c8ffa..210e491 100644 >> --- a/arch/x86/kvm/vmx.c >> +++ b/arch/x86/kvm/vmx.c >> @@ -2544,18 +2544,6 @@ static bool vmx_invpcid_supported(void) >> return cpu_has_vmx_invpcid() && enable_ept; >> } >> >> -/* >> - * Swap MSR entry in host/guest MSR entry array. >> - */ >> -static void move_msr_up(struct vcpu_vmx *vmx, int from, int to) >> -{ >> - struct shared_msr_entry tmp; >> - >> - tmp = vmx->guest_msrs[to]; >> - vmx->guest_msrs[to] = vmx->guest_msrs[from]; >> - vmx->guest_msrs[from] = tmp; >> -} >> - >> static void vmx_set_msr_bitmap(struct kvm_vcpu *vcpu) >> { >> unsigned long *msr_bitmap; >> @@ -2600,28 +2588,28 @@ static void setup_msrs(struct vcpu_vmx *vmx) >> if (is_long_mode(&vmx->vcpu)) { >> index = __find_msr_index(vmx, MSR_SYSCALL_MASK); >> if (index >= 0) >> - move_msr_up(vmx, index, save_nmsrs++); >> + swap(vmx->guest_msrs[index], vmx->guest_msrs[save_nmsrs++]); >> index = __find_msr_index(vmx, MSR_LSTAR); >> if (index >= 0) >> - move_msr_up(vmx, index, save_nmsrs++); >> + swap(vmx->guest_msrs[index], vmx->guest_msrs[save_nmsrs++]); >> index = __find_msr_index(vmx, MSR_CSTAR); >> if (index >= 0) >> - move_msr_up(vmx, index, save_nmsrs++); >> + swap(vmx->guest_msrs[index], vmx->guest_msrs[save_nmsrs++]); >> index = __find_msr_index(vmx, MSR_TSC_AUX); >> if (index >= 0 && guest_cpuid_has(&vmx->vcpu, X86_FEATURE_RDTSCP)) >> - move_msr_up(vmx, index, save_nmsrs++); >> + swap(vmx->guest_msrs[index], vmx->guest_msrs[save_nmsrs++]); >> /* >> * MSR_STAR is only needed on long mode guests, and only >> * if efer.sce is enabled. >> */ >> index = __find_msr_index(vmx, MSR_STAR); >> if ((index >= 0) && (vmx->vcpu.arch.efer & EFER_SCE)) >> - move_msr_up(vmx, index, save_nmsrs++); >> + swap(vmx->guest_msrs[index], vmx->guest_msrs[save_nmsrs++]); >> } >> #endif >> index = __find_msr_index(vmx, MSR_EFER); >> if (index >= 0 && update_transition_efer(vmx, index)) >> - move_msr_up(vmx, index, save_nmsrs++); >> + swap(vmx->guest_msrs[index], vmx->guest_msrs[save_nmsrs++]); >> >> vmx->save_nmsrs = save_nmsrs; > > >> >> -- >> 2.7.4 >> >>
diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c index e6c8ffa..210e491 100644 --- a/arch/x86/kvm/vmx.c +++ b/arch/x86/kvm/vmx.c @@ -2544,18 +2544,6 @@ static bool vmx_invpcid_supported(void) return cpu_has_vmx_invpcid() && enable_ept; } -/* - * Swap MSR entry in host/guest MSR entry array. - */ -static void move_msr_up(struct vcpu_vmx *vmx, int from, int to) -{ - struct shared_msr_entry tmp; - - tmp = vmx->guest_msrs[to]; - vmx->guest_msrs[to] = vmx->guest_msrs[from]; - vmx->guest_msrs[from] = tmp; -} - static void vmx_set_msr_bitmap(struct kvm_vcpu *vcpu) { unsigned long *msr_bitmap; @@ -2600,28 +2588,28 @@ static void setup_msrs(struct vcpu_vmx *vmx) if (is_long_mode(&vmx->vcpu)) { index = __find_msr_index(vmx, MSR_SYSCALL_MASK); if (index >= 0) - move_msr_up(vmx, index, save_nmsrs++); + swap(vmx->guest_msrs[index], vmx->guest_msrs[save_nmsrs++]); index = __find_msr_index(vmx, MSR_LSTAR); if (index >= 0) - move_msr_up(vmx, index, save_nmsrs++); + swap(vmx->guest_msrs[index], vmx->guest_msrs[save_nmsrs++]); index = __find_msr_index(vmx, MSR_CSTAR); if (index >= 0) - move_msr_up(vmx, index, save_nmsrs++); + swap(vmx->guest_msrs[index], vmx->guest_msrs[save_nmsrs++]); index = __find_msr_index(vmx, MSR_TSC_AUX); if (index >= 0 && guest_cpuid_has(&vmx->vcpu, X86_FEATURE_RDTSCP)) - move_msr_up(vmx, index, save_nmsrs++); + swap(vmx->guest_msrs[index], vmx->guest_msrs[save_nmsrs++]); /* * MSR_STAR is only needed on long mode guests, and only * if efer.sce is enabled. */ index = __find_msr_index(vmx, MSR_STAR); if ((index >= 0) && (vmx->vcpu.arch.efer & EFER_SCE)) - move_msr_up(vmx, index, save_nmsrs++); + swap(vmx->guest_msrs[index], vmx->guest_msrs[save_nmsrs++]); } #endif index = __find_msr_index(vmx, MSR_EFER); if (index >= 0 && update_transition_efer(vmx, index)) - move_msr_up(vmx, index, save_nmsrs++); + swap(vmx->guest_msrs[index], vmx->guest_msrs[save_nmsrs++]); vmx->save_nmsrs = save_nmsrs;
Function move_msr_up is used to _manually_ swap MSR entries in MSR array. This function can be removed and replaced using the swap macro instead. This code was detected with the help of Coccinelle. Signed-off-by: Gustavo A. R. Silva <garsilva@embeddedor.com> --- The new lines are over 80 characters, but I think in this case that is preferable over splitting them. arch/x86/kvm/vmx.c | 24 ++++++------------------ 1 file changed, 6 insertions(+), 18 deletions(-)