On Wed, 2022-11-30 at 23:09 +0000, Sean Christopherson wrote:
> Move the .check_processor_compatibility() callback from kvm_x86_init_ops
> to kvm_x86_ops to allow a future patch to do compatibility checks during
> CPU hotplug.
>
> Do kvm_ops_update() before compat checks so that static_call() can be
> used during compat checks.
>
> Signed-off-by: Sean Christopherson <seanjc@xxxxxxxxxx>
Reviewed-by: Kai Huang <kai.huang@xxxxxxxxx>
> ---
> arch/x86/include/asm/kvm-x86-ops.h | 1 +
> arch/x86/include/asm/kvm_host.h | 3 ++-
> arch/x86/kvm/svm/svm.c | 5 +++--
> arch/x86/kvm/vmx/vmx.c | 16 +++++++--------
> arch/x86/kvm/x86.c | 31 +++++++++++-------------------
> 5 files changed, 25 insertions(+), 31 deletions(-)
>
> diff --git a/arch/x86/include/asm/kvm-x86-ops.h b/arch/x86/include/asm/kvm-x86-ops.h
> index abccd51dcfca..dba2909e5ae2 100644
> --- a/arch/x86/include/asm/kvm-x86-ops.h
> +++ b/arch/x86/include/asm/kvm-x86-ops.h
> @@ -14,6 +14,7 @@ BUILD_BUG_ON(1)
> * to make a definition optional, but in this case the default will
> * be __static_call_return0.
> */
> +KVM_X86_OP(check_processor_compatibility)
> KVM_X86_OP(hardware_enable)
> KVM_X86_OP(hardware_disable)
> KVM_X86_OP(hardware_unsetup)
> diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h
> index d79aedf70908..ba74fea6850b 100644
> --- a/arch/x86/include/asm/kvm_host.h
> +++ b/arch/x86/include/asm/kvm_host.h
> @@ -1518,6 +1518,8 @@ static inline u16 kvm_lapic_irq_dest_mode(bool dest_mode_logical)
> struct kvm_x86_ops {
> const char *name;
>
> + int (*check_processor_compatibility)(void);
> +
> int (*hardware_enable)(void);
> void (*hardware_disable)(void);
> void (*hardware_unsetup)(void);
> @@ -1729,7 +1731,6 @@ struct kvm_x86_nested_ops {
> };
>
> struct kvm_x86_init_ops {
> - int (*check_processor_compatibility)(void);
> int (*hardware_setup)(void);
> unsigned int (*handle_intel_pt_intr)(void);
>
> diff --git a/arch/x86/kvm/svm/svm.c b/arch/x86/kvm/svm/svm.c
> index 9f94efcb9aa6..c2e95c0d9fd8 100644
> --- a/arch/x86/kvm/svm/svm.c
> +++ b/arch/x86/kvm/svm/svm.c
> @@ -543,7 +543,7 @@ static bool kvm_is_svm_supported(void)
> return true;
> }
>
> -static int __init svm_check_processor_compat(void)
> +static int svm_check_processor_compat(void)
> {
> if (!kvm_is_svm_supported())
> return -EIO;
> @@ -4695,6 +4695,8 @@ static int svm_vm_init(struct kvm *kvm)
> static struct kvm_x86_ops svm_x86_ops __initdata = {
> .name = KBUILD_MODNAME,
>
> + .check_processor_compatibility = svm_check_processor_compat,
> +
> .hardware_unsetup = svm_hardware_unsetup,
> .hardware_enable = svm_hardware_enable,
> .hardware_disable = svm_hardware_disable,
> @@ -5079,7 +5081,6 @@ static __init int svm_hardware_setup(void)
>
> static struct kvm_x86_init_ops svm_init_ops __initdata = {
> .hardware_setup = svm_hardware_setup,
> - .check_processor_compatibility = svm_check_processor_compat,
>
> .runtime_ops = &svm_x86_ops,
> .pmu_ops = &amd_pmu_ops,
> diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c
> index 2a8a6e481c76..6416ed5b7f89 100644
> --- a/arch/x86/kvm/vmx/vmx.c
> +++ b/arch/x86/kvm/vmx/vmx.c
> @@ -2520,8 +2520,7 @@ static bool cpu_has_perf_global_ctrl_bug(void)
> return false;
> }
>
> -static __init int adjust_vmx_controls(u32 ctl_min, u32 ctl_opt,
> - u32 msr, u32 *result)
> +static int adjust_vmx_controls(u32 ctl_min, u32 ctl_opt, u32 msr, u32 *result)
> {
> u32 vmx_msr_low, vmx_msr_high;
> u32 ctl = ctl_min | ctl_opt;
> @@ -2539,7 +2538,7 @@ static __init int adjust_vmx_controls(u32 ctl_min, u32 ctl_opt,
> return 0;
> }
>
> -static __init u64 adjust_vmx_controls64(u64 ctl_opt, u32 msr)
> +static u64 adjust_vmx_controls64(u64 ctl_opt, u32 msr)
> {
> u64 allowed;
>
> @@ -2548,8 +2547,8 @@ static __init u64 adjust_vmx_controls64(u64 ctl_opt, u32 msr)
> return ctl_opt & allowed;
> }
>
> -static __init int setup_vmcs_config(struct vmcs_config *vmcs_conf,
> - struct vmx_capability *vmx_cap)
> +static int setup_vmcs_config(struct vmcs_config *vmcs_conf,
> + struct vmx_capability *vmx_cap)
> {
> u32 vmx_msr_low, vmx_msr_high;
> u32 _pin_based_exec_control = 0;
> @@ -2710,7 +2709,7 @@ static __init int setup_vmcs_config(struct vmcs_config *vmcs_conf,
> return 0;
> }
>
> -static bool __init kvm_is_vmx_supported(void)
> +static bool kvm_is_vmx_supported(void)
> {
> if (!cpu_has_vmx()) {
> pr_err("CPU doesn't support VMX\n");
> @@ -2726,7 +2725,7 @@ static bool __init kvm_is_vmx_supported(void)
> return true;
> }
>
> -static int __init vmx_check_processor_compat(void)
> +static int vmx_check_processor_compat(void)
> {
> struct vmcs_config vmcs_conf;
> struct vmx_capability vmx_cap;
> @@ -8104,6 +8103,8 @@ static void vmx_vm_destroy(struct kvm *kvm)
> static struct kvm_x86_ops vmx_x86_ops __initdata = {
> .name = KBUILD_MODNAME,
>
> + .check_processor_compatibility = vmx_check_processor_compat,
> +
> .hardware_unsetup = vmx_hardware_unsetup,
>
> .hardware_enable = vmx_hardware_enable,
> @@ -8501,7 +8502,6 @@ static __init int hardware_setup(void)
> }
>
> static struct kvm_x86_init_ops vmx_init_ops __initdata = {
> - .check_processor_compatibility = vmx_check_processor_compat,
> .hardware_setup = hardware_setup,
> .handle_intel_pt_intr = NULL,
>
> diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
> index 5551f3552f08..ee9af412ffd4 100644
> --- a/arch/x86/kvm/x86.c
> +++ b/arch/x86/kvm/x86.c
> @@ -9279,12 +9279,7 @@ 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)
> +static int kvm_x86_check_processor_compatibility(void)
> {
> struct cpuinfo_x86 *c = &cpu_data(smp_processor_id());
>
> @@ -9294,19 +9289,16 @@ static int kvm_x86_check_processor_compatibility(struct kvm_x86_init_ops *ops)
> __cr4_reserved_bits(cpu_has, &boot_cpu_data))
> return -EIO;
>
> - return ops->check_processor_compatibility();
> + return static_call(kvm_x86_check_processor_compatibility)();
> }
>
> -static void kvm_x86_check_cpu_compat(void *data)
> +static void kvm_x86_check_cpu_compat(void *ret)
> {
> - struct kvm_cpu_compat_check *c = data;
> -
> - *c->ret = kvm_x86_check_processor_compatibility(c->ops);
> + *(int *)ret = kvm_x86_check_processor_compatibility();
> }
>
> static int __kvm_x86_vendor_init(struct kvm_x86_init_ops *ops)
> {
> - struct kvm_cpu_compat_check c;
> u64 host_pat;
> int r, cpu;
>
> @@ -9377,12 +9369,12 @@ 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;
> + kvm_ops_update(ops);
> +
> for_each_online_cpu(cpu) {
> - smp_call_function_single(cpu, kvm_x86_check_cpu_compat, &c, 1);
> + smp_call_function_single(cpu, kvm_x86_check_cpu_compat, &r, 1);
> if (r < 0)
> - goto out_hardware_unsetup;
> + goto out_unwind_ops;
> }
>
> /*
> @@ -9390,8 +9382,6 @@ static int __kvm_x86_vendor_init(struct kvm_x86_init_ops *ops)
> * absolutely necessary, as most operations from this point forward
> * require unwinding.
> */
> - kvm_ops_update(ops);
> -
> kvm_timer_init();
>
> if (pi_inject_timer == -1)
> @@ -9427,8 +9417,9 @@ 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_unwind_ops:
> + kvm_x86_ops.hardware_enable = NULL;
> + static_call(kvm_x86_hardware_unsetup)();
> out_mmu_exit:
> kvm_mmu_vendor_module_exit();
> out_free_percpu:
