From: David Matlack <dmatlack@google.com>
Use kvm_arch_flush_remote_tlbs() instead of
CONFIG_HAVE_KVM_ARCH_TLB_FLUSH_ALL. The two mechanisms solve the same
problem, allowing architecture-specific code to provide a non-IPI
implementation of remote TLB flushing.
Dropping CONFIG_HAVE_KVM_ARCH_TLB_FLUSH_ALL allows KVM to standardize
all architectures on kvm_arch_flush_remote_tlbs() instead of maintaining
two mechanisms.
Opt to standardize on kvm_arch_flush_remote_tlbs() since it avoids
duplicating the generic TLB stats across architectures that implement
their own remote TLB flush.
This adds an extra function call to the ARM64 kvm_flush_remote_tlbs()
path, but that is a small cost in comparison to flushing remote TLBs.
In addition, instead of just incrementing remote_tlb_flush_requests
stat, the generic interface would also increment the
remote_tlb_flush stat.
Signed-off-by: David Matlack <dmatlack@google.com>
Signed-off-by: Raghavendra Rao Ananta <rananta@google.com>
Reviewed-by: Zenghui Yu <zenghui.yu@linux.dev>
Acked-by: Oliver Upton <oliver.upton@linux.dev>
Reviewed-by: Gavin Shan <gshan@redhat.com>
---
arch/arm64/include/asm/kvm_host.h | 3 +++
arch/arm64/kvm/Kconfig | 1 -
arch/arm64/kvm/mmu.c | 6 +++---
virt/kvm/Kconfig | 3 ---
virt/kvm/kvm_main.c | 2 --
5 files changed, 6 insertions(+), 9 deletions(-)
diff --git a/arch/arm64/include/asm/kvm_host.h b/arch/arm64/include/asm/kvm_host.h
index 8b6096753740..7281222f24ef 100644
--- a/arch/arm64/include/asm/kvm_host.h
+++ b/arch/arm64/include/asm/kvm_host.h
@@ -1111,6 +1111,9 @@ int __init kvm_set_ipa_limit(void);
#define __KVM_HAVE_ARCH_VM_ALLOC
struct kvm *kvm_arch_alloc_vm(void);
+#define __KVM_HAVE_ARCH_FLUSH_REMOTE_TLBS
+int kvm_arch_flush_remote_tlbs(struct kvm *kvm);
+
static inline bool kvm_vm_is_protected(struct kvm *kvm)
{
return false;
diff --git a/arch/arm64/kvm/Kconfig b/arch/arm64/kvm/Kconfig
index f531da6b362e..6b730fcfee37 100644
--- a/arch/arm64/kvm/Kconfig
+++ b/arch/arm64/kvm/Kconfig
@@ -25,7 +25,6 @@ menuconfig KVM
select MMU_NOTIFIER
select PREEMPT_NOTIFIERS
select HAVE_KVM_CPU_RELAX_INTERCEPT
- select HAVE_KVM_ARCH_TLB_FLUSH_ALL
select KVM_MMIO
select KVM_GENERIC_DIRTYLOG_READ_PROTECT
select KVM_XFER_TO_GUEST_WORK
diff --git a/arch/arm64/kvm/mmu.c b/arch/arm64/kvm/mmu.c
index 6db9ef288ec3..0ac721fa27f1 100644
--- a/arch/arm64/kvm/mmu.c
+++ b/arch/arm64/kvm/mmu.c
@@ -161,15 +161,15 @@ static bool memslot_is_logging(struct kvm_memory_slot *memslot)
}
/**
- * kvm_flush_remote_tlbs() - flush all VM TLB entries for v7/8
+ * kvm_arch_flush_remote_tlbs() - flush all VM TLB entries for v7/8
* @kvm: pointer to kvm structure.
*
* Interface to HYP function to flush all VM TLB entries
*/
-void kvm_flush_remote_tlbs(struct kvm *kvm)
+int kvm_arch_flush_remote_tlbs(struct kvm *kvm)
{
- ++kvm->stat.generic.remote_tlb_flush_requests;
kvm_call_hyp(__kvm_tlb_flush_vmid, &kvm->arch.mmu);
+ return 0;
}
static bool kvm_is_device_pfn(unsigned long pfn)
diff --git a/virt/kvm/Kconfig b/virt/kvm/Kconfig
index b74916de5183..484d0873061c 100644
--- a/virt/kvm/Kconfig
+++ b/virt/kvm/Kconfig
@@ -62,9 +62,6 @@ config HAVE_KVM_CPU_RELAX_INTERCEPT
config KVM_VFIO
bool
-config HAVE_KVM_ARCH_TLB_FLUSH_ALL
- bool
-
config HAVE_KVM_INVALID_WAKEUPS
bool
diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c
index 70e5479797ac..d6b050786155 100644
--- a/virt/kvm/kvm_main.c
+++ b/virt/kvm/kvm_main.c
@@ -345,7 +345,6 @@ bool kvm_make_all_cpus_request(struct kvm *kvm, unsigned int req)
}
EXPORT_SYMBOL_GPL(kvm_make_all_cpus_request);
-#ifndef CONFIG_HAVE_KVM_ARCH_TLB_FLUSH_ALL
void kvm_flush_remote_tlbs(struct kvm *kvm)
{
++kvm->stat.generic.remote_tlb_flush_requests;
@@ -366,7 +365,6 @@ void kvm_flush_remote_tlbs(struct kvm *kvm)
++kvm->stat.generic.remote_tlb_flush;
}
EXPORT_SYMBOL_GPL(kvm_flush_remote_tlbs);
-#endif
static void kvm_flush_shadow_all(struct kvm *kvm)
{
--
2.41.0.455.g037347b96a-googHi Raghavendra, David, On 15/7/23 02:53, Raghavendra Rao Ananta wrote: > From: David Matlack <dmatlack@google.com> > > Use kvm_arch_flush_remote_tlbs() instead of > CONFIG_HAVE_KVM_ARCH_TLB_FLUSH_ALL. The two mechanisms solve the same > problem, allowing architecture-specific code to provide a non-IPI > implementation of remote TLB flushing. > > Dropping CONFIG_HAVE_KVM_ARCH_TLB_FLUSH_ALL allows KVM to standardize > all architectures on kvm_arch_flush_remote_tlbs() instead of maintaining > two mechanisms. > > Opt to standardize on kvm_arch_flush_remote_tlbs() since it avoids > duplicating the generic TLB stats across architectures that implement > their own remote TLB flush. > > This adds an extra function call to the ARM64 kvm_flush_remote_tlbs() > path, but that is a small cost in comparison to flushing remote TLBs. > > In addition, instead of just incrementing remote_tlb_flush_requests > stat, the generic interface would also increment the > remote_tlb_flush stat. > > Signed-off-by: David Matlack <dmatlack@google.com> > Signed-off-by: Raghavendra Rao Ananta <rananta@google.com> > Reviewed-by: Zenghui Yu <zenghui.yu@linux.dev> > Acked-by: Oliver Upton <oliver.upton@linux.dev> > Reviewed-by: Gavin Shan <gshan@redhat.com> > --- > arch/arm64/include/asm/kvm_host.h | 3 +++ > arch/arm64/kvm/Kconfig | 1 - > arch/arm64/kvm/mmu.c | 6 +++--- > virt/kvm/Kconfig | 3 --- > virt/kvm/kvm_main.c | 2 -- > 5 files changed, 6 insertions(+), 9 deletions(-) You are doing 2 changes in the same patch: - Have ARM use kvm_arch_flush_remote_tlbs() instead of HAVE_KVM_ARCH_TLB_FLUSH_ALL, - Drop the now unused HAVE_KVM_ARCH_TLB_FLUSH_ALL. Commits should be atomic, to allow partial revert or cherry-pick. Preferably splitting this patch in 2: Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org> Regards, Phil.
Hi Philippe, On Mon, Jul 17, 2023 at 1:13 AM Philippe Mathieu-Daudé <philmd@linaro.org> wrote: > > Hi Raghavendra, David, > > On 15/7/23 02:53, Raghavendra Rao Ananta wrote: > > From: David Matlack <dmatlack@google.com> > > > > Use kvm_arch_flush_remote_tlbs() instead of > > CONFIG_HAVE_KVM_ARCH_TLB_FLUSH_ALL. The two mechanisms solve the same > > problem, allowing architecture-specific code to provide a non-IPI > > implementation of remote TLB flushing. > > > > Dropping CONFIG_HAVE_KVM_ARCH_TLB_FLUSH_ALL allows KVM to standardize > > all architectures on kvm_arch_flush_remote_tlbs() instead of maintaining > > two mechanisms. > > > > Opt to standardize on kvm_arch_flush_remote_tlbs() since it avoids > > duplicating the generic TLB stats across architectures that implement > > their own remote TLB flush. > > > > This adds an extra function call to the ARM64 kvm_flush_remote_tlbs() > > path, but that is a small cost in comparison to flushing remote TLBs. > > > > In addition, instead of just incrementing remote_tlb_flush_requests > > stat, the generic interface would also increment the > > remote_tlb_flush stat. > > > > Signed-off-by: David Matlack <dmatlack@google.com> > > Signed-off-by: Raghavendra Rao Ananta <rananta@google.com> > > Reviewed-by: Zenghui Yu <zenghui.yu@linux.dev> > > Acked-by: Oliver Upton <oliver.upton@linux.dev> > > Reviewed-by: Gavin Shan <gshan@redhat.com> > > --- > > arch/arm64/include/asm/kvm_host.h | 3 +++ > > arch/arm64/kvm/Kconfig | 1 - > > arch/arm64/kvm/mmu.c | 6 +++--- > > virt/kvm/Kconfig | 3 --- > > virt/kvm/kvm_main.c | 2 -- > > 5 files changed, 6 insertions(+), 9 deletions(-) > > You are doing 2 changes in the same patch: > > - Have ARM use kvm_arch_flush_remote_tlbs() instead of > HAVE_KVM_ARCH_TLB_FLUSH_ALL, > - Drop the now unused HAVE_KVM_ARCH_TLB_FLUSH_ALL. > > Commits should be atomic, to allow partial > revert or cherry-pick. > > Preferably splitting this patch in 2: > Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org> > Thanks for the suggestion. I guess that makes sense. I'll split the patch in two for v7. - Raghavendra > Regards, > > Phil. >
On 7/15/23 08:53, Raghavendra Rao Ananta wrote:
> From: David Matlack <dmatlack@google.com>
>
> Use kvm_arch_flush_remote_tlbs() instead of
> CONFIG_HAVE_KVM_ARCH_TLB_FLUSH_ALL. The two mechanisms solve the same
> problem, allowing architecture-specific code to provide a non-IPI
> implementation of remote TLB flushing.
>
> Dropping CONFIG_HAVE_KVM_ARCH_TLB_FLUSH_ALL allows KVM to standardize
> all architectures on kvm_arch_flush_remote_tlbs() instead of maintaining
> two mechanisms.
>
> Opt to standardize on kvm_arch_flush_remote_tlbs() since it avoids
> duplicating the generic TLB stats across architectures that implement
> their own remote TLB flush.
>
> This adds an extra function call to the ARM64 kvm_flush_remote_tlbs()
> path, but that is a small cost in comparison to flushing remote TLBs.
>
> In addition, instead of just incrementing remote_tlb_flush_requests
> stat, the generic interface would also increment the
> remote_tlb_flush stat.
>
> Signed-off-by: David Matlack <dmatlack@google.com>
> Signed-off-by: Raghavendra Rao Ananta <rananta@google.com>
> Reviewed-by: Zenghui Yu <zenghui.yu@linux.dev>
> Acked-by: Oliver Upton <oliver.upton@linux.dev>
> Reviewed-by: Gavin Shan <gshan@redhat.com>
Reviewed-by: Shaoqin Huang <shahuang@redhat.com>
> ---
> arch/arm64/include/asm/kvm_host.h | 3 +++
> arch/arm64/kvm/Kconfig | 1 -
> arch/arm64/kvm/mmu.c | 6 +++---
> virt/kvm/Kconfig | 3 ---
> virt/kvm/kvm_main.c | 2 --
> 5 files changed, 6 insertions(+), 9 deletions(-)
>
> diff --git a/arch/arm64/include/asm/kvm_host.h b/arch/arm64/include/asm/kvm_host.h
> index 8b6096753740..7281222f24ef 100644
> --- a/arch/arm64/include/asm/kvm_host.h
> +++ b/arch/arm64/include/asm/kvm_host.h
> @@ -1111,6 +1111,9 @@ int __init kvm_set_ipa_limit(void);
> #define __KVM_HAVE_ARCH_VM_ALLOC
> struct kvm *kvm_arch_alloc_vm(void);
>
> +#define __KVM_HAVE_ARCH_FLUSH_REMOTE_TLBS
> +int kvm_arch_flush_remote_tlbs(struct kvm *kvm);
> +
> static inline bool kvm_vm_is_protected(struct kvm *kvm)
> {
> return false;
> diff --git a/arch/arm64/kvm/Kconfig b/arch/arm64/kvm/Kconfig
> index f531da6b362e..6b730fcfee37 100644
> --- a/arch/arm64/kvm/Kconfig
> +++ b/arch/arm64/kvm/Kconfig
> @@ -25,7 +25,6 @@ menuconfig KVM
> select MMU_NOTIFIER
> select PREEMPT_NOTIFIERS
> select HAVE_KVM_CPU_RELAX_INTERCEPT
> - select HAVE_KVM_ARCH_TLB_FLUSH_ALL
> select KVM_MMIO
> select KVM_GENERIC_DIRTYLOG_READ_PROTECT
> select KVM_XFER_TO_GUEST_WORK
> diff --git a/arch/arm64/kvm/mmu.c b/arch/arm64/kvm/mmu.c
> index 6db9ef288ec3..0ac721fa27f1 100644
> --- a/arch/arm64/kvm/mmu.c
> +++ b/arch/arm64/kvm/mmu.c
> @@ -161,15 +161,15 @@ static bool memslot_is_logging(struct kvm_memory_slot *memslot)
> }
>
> /**
> - * kvm_flush_remote_tlbs() - flush all VM TLB entries for v7/8
> + * kvm_arch_flush_remote_tlbs() - flush all VM TLB entries for v7/8
> * @kvm: pointer to kvm structure.
> *
> * Interface to HYP function to flush all VM TLB entries
> */
> -void kvm_flush_remote_tlbs(struct kvm *kvm)
> +int kvm_arch_flush_remote_tlbs(struct kvm *kvm)
> {
> - ++kvm->stat.generic.remote_tlb_flush_requests;
> kvm_call_hyp(__kvm_tlb_flush_vmid, &kvm->arch.mmu);
> + return 0;
> }
>
> static bool kvm_is_device_pfn(unsigned long pfn)
> diff --git a/virt/kvm/Kconfig b/virt/kvm/Kconfig
> index b74916de5183..484d0873061c 100644
> --- a/virt/kvm/Kconfig
> +++ b/virt/kvm/Kconfig
> @@ -62,9 +62,6 @@ config HAVE_KVM_CPU_RELAX_INTERCEPT
> config KVM_VFIO
> bool
>
> -config HAVE_KVM_ARCH_TLB_FLUSH_ALL
> - bool
> -
> config HAVE_KVM_INVALID_WAKEUPS
> bool
>
> diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c
> index 70e5479797ac..d6b050786155 100644
> --- a/virt/kvm/kvm_main.c
> +++ b/virt/kvm/kvm_main.c
> @@ -345,7 +345,6 @@ bool kvm_make_all_cpus_request(struct kvm *kvm, unsigned int req)
> }
> EXPORT_SYMBOL_GPL(kvm_make_all_cpus_request);
>
> -#ifndef CONFIG_HAVE_KVM_ARCH_TLB_FLUSH_ALL
> void kvm_flush_remote_tlbs(struct kvm *kvm)
> {
> ++kvm->stat.generic.remote_tlb_flush_requests;
> @@ -366,7 +365,6 @@ void kvm_flush_remote_tlbs(struct kvm *kvm)
> ++kvm->stat.generic.remote_tlb_flush;
> }
> EXPORT_SYMBOL_GPL(kvm_flush_remote_tlbs);
> -#endif
>
> static void kvm_flush_shadow_all(struct kvm *kvm)
> {
--
Shaoqin
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