[PATCH v2 6/7] KVM: Allow range-based TLB invalidation from common code
David Matlack
dmatlack at google.com
Thu Jan 26 10:40:24 PST 2023
Make kvm_flush_remote_tlbs_range() visible in common code and create a
default implementation that just invalidates the whole TLB.
This paves the way for several future features/cleanups:
- Introduction of range-based TLBI on ARM.
- Eliminating kvm_arch_flush_remote_tlbs_memslot()
- Moving the KVM/x86 TDP MMU to common code.
No functional change intended.
Signed-off-by: David Matlack <dmatlack at google.com>
---
arch/x86/include/asm/kvm_host.h | 3 +++
arch/x86/kvm/mmu/mmu.c | 5 ++---
arch/x86/kvm/mmu/mmu_internal.h | 2 --
include/linux/kvm_host.h | 9 +++++++++
virt/kvm/kvm_main.c | 13 +++++++++++++
5 files changed, 27 insertions(+), 5 deletions(-)
diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h
index 561d31d9a7da..6b2d6ced87ef 100644
--- a/arch/x86/include/asm/kvm_host.h
+++ b/arch/x86/include/asm/kvm_host.h
@@ -1816,6 +1816,9 @@ static inline int kvm_arch_flush_remote_tlbs(struct kvm *kvm)
return -ENOTSUPP;
}
+#define __KVM_HAVE_ARCH_FLUSH_REMOTE_TLBS_RANGE
+int kvm_arch_flush_remote_tlbs_range(struct kvm *kvm, gfn_t start_gfn, u64 pages);
+
#define kvm_arch_pmi_in_guest(vcpu) \
((vcpu) && (vcpu)->arch.handling_intr_from_guest)
diff --git a/arch/x86/kvm/mmu/mmu.c b/arch/x86/kvm/mmu/mmu.c
index 34b670e719af..284c812db63b 100644
--- a/arch/x86/kvm/mmu/mmu.c
+++ b/arch/x86/kvm/mmu/mmu.c
@@ -247,7 +247,7 @@ static inline bool kvm_available_flush_tlb_with_range(void)
return kvm_x86_ops.tlb_remote_flush_with_range;
}
-void kvm_flush_remote_tlbs_range(struct kvm *kvm, gfn_t start_gfn, u64 pages)
+int kvm_arch_flush_remote_tlbs_range(struct kvm *kvm, gfn_t start_gfn, u64 pages)
{
struct kvm_tlb_range range;
int ret = -EOPNOTSUPP;
@@ -258,8 +258,7 @@ void kvm_flush_remote_tlbs_range(struct kvm *kvm, gfn_t start_gfn, u64 pages)
if (kvm_x86_ops.tlb_remote_flush_with_range)
ret = static_call(kvm_x86_tlb_remote_flush_with_range)(kvm, &range);
- if (ret)
- kvm_flush_remote_tlbs(kvm);
+ return ret;
}
static gfn_t kvm_mmu_page_get_gfn(struct kvm_mmu_page *sp, int index);
diff --git a/arch/x86/kvm/mmu/mmu_internal.h b/arch/x86/kvm/mmu/mmu_internal.h
index 0dba4d8304a6..45de82d8e162 100644
--- a/arch/x86/kvm/mmu/mmu_internal.h
+++ b/arch/x86/kvm/mmu/mmu_internal.h
@@ -170,8 +170,6 @@ bool kvm_mmu_slot_gfn_write_protect(struct kvm *kvm,
struct kvm_memory_slot *slot, u64 gfn,
int min_level);
-void kvm_flush_remote_tlbs_range(struct kvm *kvm, gfn_t start_gfn, u64 pages);
-
/* Flush the given page (huge or not) of guest memory. */
static inline void kvm_flush_remote_tlbs_gfn(struct kvm *kvm, gfn_t gfn, int level)
{
diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h
index 9366fea46e30..276187f084c8 100644
--- a/include/linux/kvm_host.h
+++ b/include/linux/kvm_host.h
@@ -1356,6 +1356,7 @@ int kvm_vcpu_yield_to(struct kvm_vcpu *target);
void kvm_vcpu_on_spin(struct kvm_vcpu *vcpu, bool yield_to_kernel_mode);
void kvm_flush_remote_tlbs(struct kvm *kvm);
+void kvm_flush_remote_tlbs_range(struct kvm *kvm, gfn_t gfn, u64 pages);
#ifdef KVM_ARCH_NR_OBJS_PER_MEMORY_CACHE
int kvm_mmu_topup_memory_cache(struct kvm_mmu_memory_cache *mc, int min);
@@ -1484,6 +1485,14 @@ static inline int kvm_arch_flush_remote_tlbs(struct kvm *kvm)
}
#endif
+#ifndef __KVM_HAVE_ARCH_FLUSH_REMOTE_TLBS_RANGE
+static inline int kvm_arch_flush_remote_tlbs_range(struct kvm *kvm,
+ gfn_t gfn, u64 pages)
+{
+ return -EOPNOTSUPP;
+}
+#endif
+
#ifdef __KVM_HAVE_ARCH_NONCOHERENT_DMA
void kvm_arch_register_noncoherent_dma(struct kvm *kvm);
void kvm_arch_unregister_noncoherent_dma(struct kvm *kvm);
diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c
index fefd3e3c8fe1..c9fc693a39d9 100644
--- a/virt/kvm/kvm_main.c
+++ b/virt/kvm/kvm_main.c
@@ -368,6 +368,19 @@ void kvm_flush_remote_tlbs(struct kvm *kvm)
}
EXPORT_SYMBOL_GPL(kvm_flush_remote_tlbs);
+void kvm_flush_remote_tlbs_range(struct kvm *kvm, gfn_t gfn, u64 pages)
+{
+ if (!kvm_arch_flush_remote_tlbs_range(kvm, gfn, pages))
+ return;
+
+ /*
+ * Fall back to a flushing entire TLBs if the architecture range-based
+ * TLB invalidation is unsupported or can't be performed for whatever
+ * reason.
+ */
+ kvm_flush_remote_tlbs(kvm);
+}
+
static void kvm_flush_shadow_all(struct kvm *kvm)
{
kvm_arch_flush_shadow_all(kvm);
--
2.39.1.456.gfc5497dd1b-goog
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