On Fri, Oct 27, 2023 at 7:22 PM Sean Christopherson <seanjc@xxxxxxxxxx> wrote:
>
> Convert KVM_ARCH_WANT_MMU_NOTIFIER into a Kconfig and select it where
> appropriate to effectively maintain existing behavior. Using a proper
> Kconfig will simplify building more functionality on top of KVM's
> mmu_notifier infrastructure.
>
> Add a forward declaration of kvm_gfn_range to kvm_types.h so that
> including arch/powerpc/include/asm/kvm_ppc.h's with CONFIG_KVM=n doesn't
> generate warnings due to kvm_gfn_range being undeclared. PPC defines
> hooks for PR vs. HV without guarding them via #ifdeffery, e.g.
>
> bool (*unmap_gfn_range)(struct kvm *kvm, struct kvm_gfn_range *range);
> bool (*age_gfn)(struct kvm *kvm, struct kvm_gfn_range *range);
> bool (*test_age_gfn)(struct kvm *kvm, struct kvm_gfn_range *range);
> bool (*set_spte_gfn)(struct kvm *kvm, struct kvm_gfn_range *range);
>
> Alternatively, PPC could forward declare kvm_gfn_range, but there's no
> good reason not to define it in common KVM.
>
> Acked-by: Anup Patel <anup@xxxxxxxxxxxxxx>
> Signed-off-by: Sean Christopherson <seanjc@xxxxxxxxxx>
> ---
Reviewed-by: Fuad Tabba <tabba@xxxxxxxxxx>
Tested-by: Fuad Tabba <tabba@xxxxxxxxxx>
(Tested x86 and arm64 on qemu)
Cheers,
/fuad
> arch/arm64/include/asm/kvm_host.h | 2 --
> arch/arm64/kvm/Kconfig | 2 +-
> arch/mips/include/asm/kvm_host.h | 2 --
> arch/mips/kvm/Kconfig | 2 +-
> arch/powerpc/include/asm/kvm_host.h | 2 --
> arch/powerpc/kvm/Kconfig | 8 ++++----
> arch/powerpc/kvm/powerpc.c | 4 +---
> arch/riscv/include/asm/kvm_host.h | 2 --
> arch/riscv/kvm/Kconfig | 2 +-
> arch/x86/include/asm/kvm_host.h | 2 --
> arch/x86/kvm/Kconfig | 2 +-
> include/linux/kvm_host.h | 6 +++---
> include/linux/kvm_types.h | 1 +
> virt/kvm/Kconfig | 4 ++++
> virt/kvm/kvm_main.c | 10 +++++-----
> 15 files changed, 22 insertions(+), 29 deletions(-)
>
> diff --git a/arch/arm64/include/asm/kvm_host.h b/arch/arm64/include/asm/kvm_host.h
> index af06ccb7ee34..9e046b64847a 100644
> --- a/arch/arm64/include/asm/kvm_host.h
> +++ b/arch/arm64/include/asm/kvm_host.h
> @@ -921,8 +921,6 @@ int __kvm_arm_vcpu_get_events(struct kvm_vcpu *vcpu,
> int __kvm_arm_vcpu_set_events(struct kvm_vcpu *vcpu,
> struct kvm_vcpu_events *events);
>
> -#define KVM_ARCH_WANT_MMU_NOTIFIER
> -
> void kvm_arm_halt_guest(struct kvm *kvm);
> void kvm_arm_resume_guest(struct kvm *kvm);
>
> diff --git a/arch/arm64/kvm/Kconfig b/arch/arm64/kvm/Kconfig
> index 83c1e09be42e..1a777715199f 100644
> --- a/arch/arm64/kvm/Kconfig
> +++ b/arch/arm64/kvm/Kconfig
> @@ -22,7 +22,7 @@ menuconfig KVM
> bool "Kernel-based Virtual Machine (KVM) support"
> depends on HAVE_KVM
> select KVM_GENERIC_HARDWARE_ENABLING
> - select MMU_NOTIFIER
> + select KVM_GENERIC_MMU_NOTIFIER
> select PREEMPT_NOTIFIERS
> select HAVE_KVM_CPU_RELAX_INTERCEPT
> select KVM_MMIO
> diff --git a/arch/mips/include/asm/kvm_host.h b/arch/mips/include/asm/kvm_host.h
> index 54a85f1d4f2c..179f320cc231 100644
> --- a/arch/mips/include/asm/kvm_host.h
> +++ b/arch/mips/include/asm/kvm_host.h
> @@ -810,8 +810,6 @@ int kvm_mips_mkclean_gpa_pt(struct kvm *kvm, gfn_t start_gfn, gfn_t end_gfn);
> pgd_t *kvm_pgd_alloc(void);
> void kvm_mmu_free_memory_caches(struct kvm_vcpu *vcpu);
>
> -#define KVM_ARCH_WANT_MMU_NOTIFIER
> -
> /* Emulation */
> enum emulation_result update_pc(struct kvm_vcpu *vcpu, u32 cause);
> int kvm_get_badinstr(u32 *opc, struct kvm_vcpu *vcpu, u32 *out);
> diff --git a/arch/mips/kvm/Kconfig b/arch/mips/kvm/Kconfig
> index a8cdba75f98d..c04987d2ed2e 100644
> --- a/arch/mips/kvm/Kconfig
> +++ b/arch/mips/kvm/Kconfig
> @@ -25,7 +25,7 @@ config KVM
> select HAVE_KVM_EVENTFD
> select HAVE_KVM_VCPU_ASYNC_IOCTL
> select KVM_MMIO
> - select MMU_NOTIFIER
> + select KVM_GENERIC_MMU_NOTIFIER
> select INTERVAL_TREE
> select KVM_GENERIC_HARDWARE_ENABLING
> help
> diff --git a/arch/powerpc/include/asm/kvm_host.h b/arch/powerpc/include/asm/kvm_host.h
> index 14ee0dece853..4b5c3f2acf78 100644
> --- a/arch/powerpc/include/asm/kvm_host.h
> +++ b/arch/powerpc/include/asm/kvm_host.h
> @@ -62,8 +62,6 @@
>
> #include <linux/mmu_notifier.h>
>
> -#define KVM_ARCH_WANT_MMU_NOTIFIER
> -
> #define HPTEG_CACHE_NUM (1 << 15)
> #define HPTEG_HASH_BITS_PTE 13
> #define HPTEG_HASH_BITS_PTE_LONG 12
> diff --git a/arch/powerpc/kvm/Kconfig b/arch/powerpc/kvm/Kconfig
> index 902611954200..b33358ee6424 100644
> --- a/arch/powerpc/kvm/Kconfig
> +++ b/arch/powerpc/kvm/Kconfig
> @@ -42,7 +42,7 @@ config KVM_BOOK3S_64_HANDLER
> config KVM_BOOK3S_PR_POSSIBLE
> bool
> select KVM_MMIO
> - select MMU_NOTIFIER
> + select KVM_GENERIC_MMU_NOTIFIER
>
> config KVM_BOOK3S_HV_POSSIBLE
> bool
> @@ -85,7 +85,7 @@ config KVM_BOOK3S_64_HV
> tristate "KVM for POWER7 and later using hypervisor mode in host"
> depends on KVM_BOOK3S_64 && PPC_POWERNV
> select KVM_BOOK3S_HV_POSSIBLE
> - select MMU_NOTIFIER
> + select KVM_GENERIC_MMU_NOTIFIER
> select CMA
> help
> Support running unmodified book3s_64 guest kernels in
> @@ -194,7 +194,7 @@ config KVM_E500V2
> depends on !CONTEXT_TRACKING_USER
> select KVM
> select KVM_MMIO
> - select MMU_NOTIFIER
> + select KVM_GENERIC_MMU_NOTIFIER
> help
> Support running unmodified E500 guest kernels in virtual machines on
> E500v2 host processors.
> @@ -211,7 +211,7 @@ config KVM_E500MC
> select KVM
> select KVM_MMIO
> select KVM_BOOKE_HV
> - select MMU_NOTIFIER
> + select KVM_GENERIC_MMU_NOTIFIER
> help
> Support running unmodified E500MC/E5500/E6500 guest kernels in
> virtual machines on E500MC/E5500/E6500 host processors.
> diff --git a/arch/powerpc/kvm/powerpc.c b/arch/powerpc/kvm/powerpc.c
> index 8d3ec483bc2b..aac75c98a956 100644
> --- a/arch/powerpc/kvm/powerpc.c
> +++ b/arch/powerpc/kvm/powerpc.c
> @@ -632,9 +632,7 @@ int kvm_vm_ioctl_check_extension(struct kvm *kvm, long ext)
> break;
> #endif
> case KVM_CAP_SYNC_MMU:
> -#if !defined(CONFIG_MMU_NOTIFIER) || !defined(KVM_ARCH_WANT_MMU_NOTIFIER)
> - BUILD_BUG();
> -#endif
> + BUILD_BUG_ON(!IS_ENABLED(CONFIG_KVM_GENERIC_MMU_NOTIFIER));
> r = 1;
> break;
> #ifdef CONFIG_KVM_BOOK3S_HV_POSSIBLE
> diff --git a/arch/riscv/include/asm/kvm_host.h b/arch/riscv/include/asm/kvm_host.h
> index 1ebf20dfbaa6..66ee9ff483e9 100644
> --- a/arch/riscv/include/asm/kvm_host.h
> +++ b/arch/riscv/include/asm/kvm_host.h
> @@ -249,8 +249,6 @@ struct kvm_vcpu_arch {
> static inline void kvm_arch_sync_events(struct kvm *kvm) {}
> static inline void kvm_arch_sched_in(struct kvm_vcpu *vcpu, int cpu) {}
>
> -#define KVM_ARCH_WANT_MMU_NOTIFIER
> -
> #define KVM_RISCV_GSTAGE_TLB_MIN_ORDER 12
>
> void kvm_riscv_local_hfence_gvma_vmid_gpa(unsigned long vmid,
> diff --git a/arch/riscv/kvm/Kconfig b/arch/riscv/kvm/Kconfig
> index dfc237d7875b..ae2e05f050ec 100644
> --- a/arch/riscv/kvm/Kconfig
> +++ b/arch/riscv/kvm/Kconfig
> @@ -30,7 +30,7 @@ config KVM
> select KVM_GENERIC_HARDWARE_ENABLING
> select KVM_MMIO
> select KVM_XFER_TO_GUEST_WORK
> - select MMU_NOTIFIER
> + select KVM_GENERIC_MMU_NOTIFIER
> select PREEMPT_NOTIFIERS
> help
> Support hosting virtualized guest machines.
> diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h
> index 70d139406bc8..31e84668014e 100644
> --- a/arch/x86/include/asm/kvm_host.h
> +++ b/arch/x86/include/asm/kvm_host.h
> @@ -2129,8 +2129,6 @@ enum {
> # define kvm_memslots_for_spte_role(kvm, role) __kvm_memslots(kvm, 0)
> #endif
>
> -#define KVM_ARCH_WANT_MMU_NOTIFIER
> -
> int kvm_cpu_has_injectable_intr(struct kvm_vcpu *v);
> int kvm_cpu_has_interrupt(struct kvm_vcpu *vcpu);
> int kvm_cpu_has_extint(struct kvm_vcpu *v);
> diff --git a/arch/x86/kvm/Kconfig b/arch/x86/kvm/Kconfig
> index ed90f148140d..091b74599c22 100644
> --- a/arch/x86/kvm/Kconfig
> +++ b/arch/x86/kvm/Kconfig
> @@ -24,7 +24,7 @@ config KVM
> depends on HIGH_RES_TIMERS
> depends on X86_LOCAL_APIC
> select PREEMPT_NOTIFIERS
> - select MMU_NOTIFIER
> + select KVM_GENERIC_MMU_NOTIFIER
> select HAVE_KVM_IRQCHIP
> select HAVE_KVM_PFNCACHE
> select HAVE_KVM_IRQFD
> diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h
> index 11d091688346..5faba69403ac 100644
> --- a/include/linux/kvm_host.h
> +++ b/include/linux/kvm_host.h
> @@ -253,7 +253,7 @@ bool kvm_setup_async_pf(struct kvm_vcpu *vcpu, gpa_t cr2_or_gpa,
> int kvm_async_pf_wakeup_all(struct kvm_vcpu *vcpu);
> #endif
>
> -#ifdef KVM_ARCH_WANT_MMU_NOTIFIER
> +#ifdef CONFIG_KVM_GENERIC_MMU_NOTIFIER
> union kvm_mmu_notifier_arg {
> pte_t pte;
> };
> @@ -783,7 +783,7 @@ struct kvm {
> struct hlist_head irq_ack_notifier_list;
> #endif
>
> -#if defined(CONFIG_MMU_NOTIFIER) && defined(KVM_ARCH_WANT_MMU_NOTIFIER)
> +#ifdef CONFIG_KVM_GENERIC_MMU_NOTIFIER
> struct mmu_notifier mmu_notifier;
> unsigned long mmu_invalidate_seq;
> long mmu_invalidate_in_progress;
> @@ -1946,7 +1946,7 @@ extern const struct _kvm_stats_desc kvm_vm_stats_desc[];
> extern const struct kvm_stats_header kvm_vcpu_stats_header;
> extern const struct _kvm_stats_desc kvm_vcpu_stats_desc[];
>
> -#if defined(CONFIG_MMU_NOTIFIER) && defined(KVM_ARCH_WANT_MMU_NOTIFIER)
> +#ifdef CONFIG_KVM_GENERIC_MMU_NOTIFIER
> static inline int mmu_invalidate_retry(struct kvm *kvm, unsigned long mmu_seq)
> {
> if (unlikely(kvm->mmu_invalidate_in_progress))
> diff --git a/include/linux/kvm_types.h b/include/linux/kvm_types.h
> index 6f4737d5046a..9d1f7835d8c1 100644
> --- a/include/linux/kvm_types.h
> +++ b/include/linux/kvm_types.h
> @@ -6,6 +6,7 @@
> struct kvm;
> struct kvm_async_pf;
> struct kvm_device_ops;
> +struct kvm_gfn_range;
> struct kvm_interrupt;
> struct kvm_irq_routing_table;
> struct kvm_memory_slot;
> diff --git a/virt/kvm/Kconfig b/virt/kvm/Kconfig
> index 484d0873061c..ecae2914c97e 100644
> --- a/virt/kvm/Kconfig
> +++ b/virt/kvm/Kconfig
> @@ -92,3 +92,7 @@ config HAVE_KVM_PM_NOTIFIER
>
> config KVM_GENERIC_HARDWARE_ENABLING
> bool
> +
> +config KVM_GENERIC_MMU_NOTIFIER
> + select MMU_NOTIFIER
> + bool
> diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c
> index 4dba682586ee..6e708017064d 100644
> --- a/virt/kvm/kvm_main.c
> +++ b/virt/kvm/kvm_main.c
> @@ -535,7 +535,7 @@ void kvm_destroy_vcpus(struct kvm *kvm)
> }
> EXPORT_SYMBOL_GPL(kvm_destroy_vcpus);
>
> -#if defined(CONFIG_MMU_NOTIFIER) && defined(KVM_ARCH_WANT_MMU_NOTIFIER)
> +#ifdef CONFIG_KVM_GENERIC_MMU_NOTIFIER
> static inline struct kvm *mmu_notifier_to_kvm(struct mmu_notifier *mn)
> {
> return container_of(mn, struct kvm, mmu_notifier);
> @@ -960,14 +960,14 @@ static int kvm_init_mmu_notifier(struct kvm *kvm)
> return mmu_notifier_register(&kvm->mmu_notifier, current->mm);
> }
>
> -#else /* !(CONFIG_MMU_NOTIFIER && KVM_ARCH_WANT_MMU_NOTIFIER) */
> +#else /* !CONFIG_KVM_GENERIC_MMU_NOTIFIER */
>
> static int kvm_init_mmu_notifier(struct kvm *kvm)
> {
> return 0;
> }
>
> -#endif /* CONFIG_MMU_NOTIFIER && KVM_ARCH_WANT_MMU_NOTIFIER */
> +#endif /* CONFIG_KVM_GENERIC_MMU_NOTIFIER */
>
> #ifdef CONFIG_HAVE_KVM_PM_NOTIFIER
> static int kvm_pm_notifier_call(struct notifier_block *bl,
> @@ -1287,7 +1287,7 @@ static struct kvm *kvm_create_vm(unsigned long type, const char *fdname)
> out_err_no_debugfs:
> kvm_coalesced_mmio_free(kvm);
> out_no_coalesced_mmio:
> -#if defined(CONFIG_MMU_NOTIFIER) && defined(KVM_ARCH_WANT_MMU_NOTIFIER)
> +#ifdef CONFIG_KVM_GENERIC_MMU_NOTIFIER
> if (kvm->mmu_notifier.ops)
> mmu_notifier_unregister(&kvm->mmu_notifier, current->mm);
> #endif
> @@ -1347,7 +1347,7 @@ static void kvm_destroy_vm(struct kvm *kvm)
> kvm->buses[i] = NULL;
> }
> kvm_coalesced_mmio_free(kvm);
> -#if defined(CONFIG_MMU_NOTIFIER) && defined(KVM_ARCH_WANT_MMU_NOTIFIER)
> +#ifdef CONFIG_KVM_GENERIC_MMU_NOTIFIER
> mmu_notifier_unregister(&kvm->mmu_notifier, kvm->mm);
> /*
> * At this point, pending calls to invalidate_range_start()
> --
> 2.42.0.820.g83a721a137-goog
>
