| Message ID | 20221130230934.1014142-32-seanjc@google.com |
|---|---|
| State | Accepted |
| Headers | show |
| Series | KVM: Rework kvm_init() and hardware enabling | expand |
On Wed, 2022-11-30 at 23:09 +0000, Sean Christopherson wrote: > Move the CPU compatibility checks to pure x86 code, i.e. drop x86's use > of the common kvm_x86_check_cpu_compat() arch hook. x86 is the only ^ kvm_arch_check_processor_compat() > architecture that "needs" to do per-CPU compatibility checks, moving > the logic to x86 will allow dropping the common code, and will also > give x86 more control over when/how the compatibility checks are > performed, e.g. TDX will need to enable hardware (do VMXON) in order to > perform compatibility checks. > > Signed-off-by: Sean Christopherson <seanjc@google.com> Reviewed-by: Kai Huang <kai.huang@intel.com> > --- > arch/x86/kvm/svm/svm.c | 2 +- > arch/x86/kvm/vmx/vmx.c | 2 +- > arch/x86/kvm/x86.c | 49 ++++++++++++++++++++++++++++++++---------- > 3 files changed, 40 insertions(+), 13 deletions(-) > > diff --git a/arch/x86/kvm/svm/svm.c b/arch/x86/kvm/svm/svm.c > index 19e81a99c58f..d7ea1c1175c2 100644 > --- a/arch/x86/kvm/svm/svm.c > +++ b/arch/x86/kvm/svm/svm.c > @@ -5103,7 +5103,7 @@ static int __init svm_init(void) > * Common KVM initialization _must_ come last, after this, /dev/kvm is > * exposed to userspace! > */ > - r = kvm_init(&svm_init_ops, sizeof(struct vcpu_svm), > + r = kvm_init(NULL, sizeof(struct vcpu_svm), > __alignof__(struct vcpu_svm), THIS_MODULE); > if (r) > goto err_kvm_init; > diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c > index 654d81f781da..8deb1bd60c10 100644 > --- a/arch/x86/kvm/vmx/vmx.c > +++ b/arch/x86/kvm/vmx/vmx.c > @@ -8592,7 +8592,7 @@ static int __init vmx_init(void) > * Common KVM initialization _must_ come last, after this, /dev/kvm is > * exposed to userspace! > */ > - r = kvm_init(&vmx_init_ops, sizeof(struct vcpu_vmx), > + r = kvm_init(NULL, sizeof(struct vcpu_vmx), > __alignof__(struct vcpu_vmx), THIS_MODULE); > if (r) > goto err_kvm_init; > diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c > index 66f16458aa97..3571bc968cf8 100644 > --- a/arch/x86/kvm/x86.c > +++ b/arch/x86/kvm/x86.c > @@ -9277,10 +9277,36 @@ static inline void kvm_ops_update(struct kvm_x86_init_ops *ops) > kvm_pmu_ops_update(ops->pmu_ops); > } > > +struct kvm_cpu_compat_check { > + struct kvm_x86_init_ops *ops; > + int *ret; > +}; > + > +static int kvm_x86_check_processor_compatibility(struct kvm_x86_init_ops *ops) > +{ > + struct cpuinfo_x86 *c = &cpu_data(smp_processor_id()); > + > + WARN_ON(!irqs_disabled()); > + > + if (__cr4_reserved_bits(cpu_has, c) != > + __cr4_reserved_bits(cpu_has, &boot_cpu_data)) > + return -EIO; > + > + return ops->check_processor_compatibility(); > +} > + > +static void kvm_x86_check_cpu_compat(void *data) > +{ > + struct kvm_cpu_compat_check *c = data; > + > + *c->ret = kvm_x86_check_processor_compatibility(c->ops); > +} > + > static int __kvm_x86_vendor_init(struct kvm_x86_init_ops *ops) > { > + struct kvm_cpu_compat_check c; > u64 host_pat; > - int r; > + int r, cpu; > > if (kvm_x86_ops.hardware_enable) { > pr_err("kvm: already loaded vendor module '%s'\n", kvm_x86_ops.name); > @@ -9360,6 +9386,14 @@ static int __kvm_x86_vendor_init(struct kvm_x86_init_ops *ops) > if (r != 0) > goto out_mmu_exit; > > + c.ret = &r; > + c.ops = ops; > + for_each_online_cpu(cpu) { > + smp_call_function_single(cpu, kvm_x86_check_cpu_compat, &c, 1); > + if (r < 0) > + goto out_hardware_unsetup; > + } > + > /* > * Point of no return! DO NOT add error paths below this point unless > * absolutely necessary, as most operations from this point forward > @@ -9402,6 +9436,8 @@ static int __kvm_x86_vendor_init(struct kvm_x86_init_ops *ops) > kvm_init_msr_list(); > return 0; > > +out_hardware_unsetup: > + ops->runtime_ops->hardware_unsetup(); > out_mmu_exit: > kvm_mmu_vendor_module_exit(); > out_free_percpu: > @@ -12037,16 +12073,7 @@ void kvm_arch_hardware_disable(void) > > int kvm_arch_check_processor_compat(void *opaque) > { > - struct cpuinfo_x86 *c = &cpu_data(smp_processor_id()); > - struct kvm_x86_init_ops *ops = opaque; > - > - WARN_ON(!irqs_disabled()); > - > - if (__cr4_reserved_bits(cpu_has, c) != > - __cr4_reserved_bits(cpu_has, &boot_cpu_data)) > - return -EIO; > - > - return ops->check_processor_compatibility(); > + return 0; > } > > bool kvm_vcpu_is_reset_bsp(struct kvm_vcpu *vcpu) > -- > 2.38.1.584.g0f3c55d4c2-goog >
On Wed, Nov 30, 2022 at 11:09:15PM +0000, Sean Christopherson <seanjc@google.com> wrote: > Move the CPU compatibility checks to pure x86 code, i.e. drop x86's use > of the common kvm_x86_check_cpu_compat() arch hook. x86 is the only > architecture that "needs" to do per-CPU compatibility checks, moving > the logic to x86 will allow dropping the common code, and will also > give x86 more control over when/how the compatibility checks are > performed, e.g. TDX will need to enable hardware (do VMXON) in order to > perform compatibility checks. > > Signed-off-by: Sean Christopherson <seanjc@google.com> > --- > arch/x86/kvm/svm/svm.c | 2 +- > arch/x86/kvm/vmx/vmx.c | 2 +- > arch/x86/kvm/x86.c | 49 ++++++++++++++++++++++++++++++++---------- > 3 files changed, 40 insertions(+), 13 deletions(-) > > diff --git a/arch/x86/kvm/svm/svm.c b/arch/x86/kvm/svm/svm.c > index 19e81a99c58f..d7ea1c1175c2 100644 > --- a/arch/x86/kvm/svm/svm.c > +++ b/arch/x86/kvm/svm/svm.c > @@ -5103,7 +5103,7 @@ static int __init svm_init(void) > * Common KVM initialization _must_ come last, after this, /dev/kvm is > * exposed to userspace! > */ > - r = kvm_init(&svm_init_ops, sizeof(struct vcpu_svm), > + r = kvm_init(NULL, sizeof(struct vcpu_svm), > __alignof__(struct vcpu_svm), THIS_MODULE); > if (r) > goto err_kvm_init; > diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c > index 654d81f781da..8deb1bd60c10 100644 > --- a/arch/x86/kvm/vmx/vmx.c > +++ b/arch/x86/kvm/vmx/vmx.c > @@ -8592,7 +8592,7 @@ static int __init vmx_init(void) > * Common KVM initialization _must_ come last, after this, /dev/kvm is > * exposed to userspace! > */ > - r = kvm_init(&vmx_init_ops, sizeof(struct vcpu_vmx), > + r = kvm_init(NULL, sizeof(struct vcpu_vmx), > __alignof__(struct vcpu_vmx), THIS_MODULE); > if (r) > goto err_kvm_init; > diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c > index 66f16458aa97..3571bc968cf8 100644 > --- a/arch/x86/kvm/x86.c > +++ b/arch/x86/kvm/x86.c > @@ -9277,10 +9277,36 @@ static inline void kvm_ops_update(struct kvm_x86_init_ops *ops) > kvm_pmu_ops_update(ops->pmu_ops); > } > > +struct kvm_cpu_compat_check { > + struct kvm_x86_init_ops *ops; > + int *ret; minor nitpick: just int ret. I don't see the necessity of the pointer. Anyway overall it looks good to me. Reviewed-by: Isaku Yamahata <isaku.yamahata@intel.com> > +}; > + > +static int kvm_x86_check_processor_compatibility(struct kvm_x86_init_ops *ops) > +{ > + struct cpuinfo_x86 *c = &cpu_data(smp_processor_id()); > + > + WARN_ON(!irqs_disabled()); > + > + if (__cr4_reserved_bits(cpu_has, c) != > + __cr4_reserved_bits(cpu_has, &boot_cpu_data)) > + return -EIO; > + > + return ops->check_processor_compatibility(); > +} > + > +static void kvm_x86_check_cpu_compat(void *data) > +{ > + struct kvm_cpu_compat_check *c = data; > + > + *c->ret = kvm_x86_check_processor_compatibility(c->ops); > +} > + > static int __kvm_x86_vendor_init(struct kvm_x86_init_ops *ops) > { > + struct kvm_cpu_compat_check c; > u64 host_pat; > - int r; > + int r, cpu; > > if (kvm_x86_ops.hardware_enable) { > pr_err("kvm: already loaded vendor module '%s'\n", kvm_x86_ops.name); > @@ -9360,6 +9386,14 @@ static int __kvm_x86_vendor_init(struct kvm_x86_init_ops *ops) > if (r != 0) > goto out_mmu_exit; > > + c.ret = &r; > + c.ops = ops; > + for_each_online_cpu(cpu) { > + smp_call_function_single(cpu, kvm_x86_check_cpu_compat, &c, 1); > + if (r < 0) Here it can be "c.ret < 0". > + goto out_hardware_unsetup; > + } > + > /* > * Point of no return! DO NOT add error paths below this point unless > * absolutely necessary, as most operations from this point forward > @@ -9402,6 +9436,8 @@ static int __kvm_x86_vendor_init(struct kvm_x86_init_ops *ops) > kvm_init_msr_list(); > return 0; > > +out_hardware_unsetup: > + ops->runtime_ops->hardware_unsetup(); > out_mmu_exit: > kvm_mmu_vendor_module_exit(); > out_free_percpu: > @@ -12037,16 +12073,7 @@ void kvm_arch_hardware_disable(void) > > int kvm_arch_check_processor_compat(void *opaque) > { > - struct cpuinfo_x86 *c = &cpu_data(smp_processor_id()); > - struct kvm_x86_init_ops *ops = opaque; > - > - WARN_ON(!irqs_disabled()); > - > - if (__cr4_reserved_bits(cpu_has, c) != > - __cr4_reserved_bits(cpu_has, &boot_cpu_data)) > - return -EIO; > - > - return ops->check_processor_compatibility(); > + return 0; > } > > bool kvm_vcpu_is_reset_bsp(struct kvm_vcpu *vcpu) > -- > 2.38.1.584.g0f3c55d4c2-goog >
On Mon, Dec 05, 2022, Isaku Yamahata wrote: > On Wed, Nov 30, 2022 at 11:09:15PM +0000, > > index 66f16458aa97..3571bc968cf8 100644 > > --- a/arch/x86/kvm/x86.c > > +++ b/arch/x86/kvm/x86.c > > @@ -9277,10 +9277,36 @@ static inline void kvm_ops_update(struct kvm_x86_init_ops *ops) > > kvm_pmu_ops_update(ops->pmu_ops); > > } > > > > +struct kvm_cpu_compat_check { > > + struct kvm_x86_init_ops *ops; > > + int *ret; > > minor nitpick: just int ret. I don't see the necessity of the pointer. > Anyway overall it looks good to me. ... > > @@ -9360,6 +9386,14 @@ static int __kvm_x86_vendor_init(struct kvm_x86_init_ops *ops) > > if (r != 0) > > goto out_mmu_exit; > > > > + c.ret = &r; > > + c.ops = ops; > > + for_each_online_cpu(cpu) { > > + smp_call_function_single(cpu, kvm_x86_check_cpu_compat, &c, 1); > > + if (r < 0) > > Here it can be "c.ret < 0". No, because the below goto leads to "return r", i.e. "c.ret" needs to be propagated to "r". That's why the code does the admittedly funky "int *ret" thing. FWIW, this gets cleanup in the end. "struct kvm_cpu_compat_check" goes away and "&r" is passed directly to kvm_x86_check_cpu_compat. > > + goto out_hardware_unsetup;
diff --git a/arch/x86/kvm/svm/svm.c b/arch/x86/kvm/svm/svm.c index 19e81a99c58f..d7ea1c1175c2 100644 --- a/arch/x86/kvm/svm/svm.c +++ b/arch/x86/kvm/svm/svm.c @@ -5103,7 +5103,7 @@ static int __init svm_init(void) * Common KVM initialization _must_ come last, after this, /dev/kvm is * exposed to userspace! */ - r = kvm_init(&svm_init_ops, sizeof(struct vcpu_svm), + r = kvm_init(NULL, sizeof(struct vcpu_svm), __alignof__(struct vcpu_svm), THIS_MODULE); if (r) goto err_kvm_init; diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c index 654d81f781da..8deb1bd60c10 100644 --- a/arch/x86/kvm/vmx/vmx.c +++ b/arch/x86/kvm/vmx/vmx.c @@ -8592,7 +8592,7 @@ static int __init vmx_init(void) * Common KVM initialization _must_ come last, after this, /dev/kvm is * exposed to userspace! */ - r = kvm_init(&vmx_init_ops, sizeof(struct vcpu_vmx), + r = kvm_init(NULL, sizeof(struct vcpu_vmx), __alignof__(struct vcpu_vmx), THIS_MODULE); if (r) goto err_kvm_init; diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index 66f16458aa97..3571bc968cf8 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -9277,10 +9277,36 @@ static inline void kvm_ops_update(struct kvm_x86_init_ops *ops) kvm_pmu_ops_update(ops->pmu_ops); } +struct kvm_cpu_compat_check { + struct kvm_x86_init_ops *ops; + int *ret; +}; + +static int kvm_x86_check_processor_compatibility(struct kvm_x86_init_ops *ops) +{ + struct cpuinfo_x86 *c = &cpu_data(smp_processor_id()); + + WARN_ON(!irqs_disabled()); + + if (__cr4_reserved_bits(cpu_has, c) != + __cr4_reserved_bits(cpu_has, &boot_cpu_data)) + return -EIO; + + return ops->check_processor_compatibility(); +} + +static void kvm_x86_check_cpu_compat(void *data) +{ + struct kvm_cpu_compat_check *c = data; + + *c->ret = kvm_x86_check_processor_compatibility(c->ops); +} + static int __kvm_x86_vendor_init(struct kvm_x86_init_ops *ops) { + struct kvm_cpu_compat_check c; u64 host_pat; - int r; + int r, cpu; if (kvm_x86_ops.hardware_enable) { pr_err("kvm: already loaded vendor module '%s'\n", kvm_x86_ops.name); @@ -9360,6 +9386,14 @@ static int __kvm_x86_vendor_init(struct kvm_x86_init_ops *ops) if (r != 0) goto out_mmu_exit; + c.ret = &r; + c.ops = ops; + for_each_online_cpu(cpu) { + smp_call_function_single(cpu, kvm_x86_check_cpu_compat, &c, 1); + if (r < 0) + goto out_hardware_unsetup; + } + /* * Point of no return! DO NOT add error paths below this point unless * absolutely necessary, as most operations from this point forward @@ -9402,6 +9436,8 @@ static int __kvm_x86_vendor_init(struct kvm_x86_init_ops *ops) kvm_init_msr_list(); return 0; +out_hardware_unsetup: + ops->runtime_ops->hardware_unsetup(); out_mmu_exit: kvm_mmu_vendor_module_exit(); out_free_percpu: @@ -12037,16 +12073,7 @@ void kvm_arch_hardware_disable(void) int kvm_arch_check_processor_compat(void *opaque) { - struct cpuinfo_x86 *c = &cpu_data(smp_processor_id()); - struct kvm_x86_init_ops *ops = opaque; - - WARN_ON(!irqs_disabled()); - - if (__cr4_reserved_bits(cpu_has, c) != - __cr4_reserved_bits(cpu_has, &boot_cpu_data)) - return -EIO; - - return ops->check_processor_compatibility(); + return 0; } bool kvm_vcpu_is_reset_bsp(struct kvm_vcpu *vcpu)
Move the CPU compatibility checks to pure x86 code, i.e. drop x86's use of the common kvm_x86_check_cpu_compat() arch hook. x86 is the only architecture that "needs" to do per-CPU compatibility checks, moving the logic to x86 will allow dropping the common code, and will also give x86 more control over when/how the compatibility checks are performed, e.g. TDX will need to enable hardware (do VMXON) in order to perform compatibility checks. Signed-off-by: Sean Christopherson <seanjc@google.com> --- arch/x86/kvm/svm/svm.c | 2 +- arch/x86/kvm/vmx/vmx.c | 2 +- arch/x86/kvm/x86.c | 49 ++++++++++++++++++++++++++++++++---------- 3 files changed, 40 insertions(+), 13 deletions(-)