[PATCH 2/4] KVM: MIPS: rework flush_shadow_* callbacks into one that prepares the flush

Paolo Bonzini
2021-04-02T15:58:15Z

Both trap-and-emulate and VZ have a single implementation that covers
both .flush_shadow_all and .flush_shadow_memslot, and both of them end
with a call to kvm_flush_remote_tlbs.

Unify the callbacks into one and extract the call to kvm_flush_remote_tlbs.
The next patches will pull it further out of the the architecture-specific
MMU notifier functions kvm_unmap_hva_range and kvm_set_spte_hva.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
---
arch/mips/include/asm/kvm_host.h | 9 +--------
arch/mips/kvm/mips.c | 12 ++++++------
arch/mips/kvm/mmu.c | 9 ++++++---
arch/mips/kvm/trap_emul.c | 13 ++-----------
arch/mips/kvm/vz.c | 19 ++++---------------
5 files changed, 19 insertions(+), 43 deletions(-)

diff --git a/arch/mips/include/asm/kvm_host.h b/arch/mips/include/asm/kvm_host.h
index feaa77036b67..6c8c0ab53be2 100644
--- a/arch/mips/include/asm/kvm_host.h
+++ b/arch/mips/include/asm/kvm_host.h
@@ -815,14 +815,7 @@ struct kvm_mips_callbacks {
int (*vcpu_init)(struct kvm_vcpu *vcpu);
void (*vcpu_uninit)(struct kvm_vcpu *vcpu);
int (*vcpu_setup)(struct kvm_vcpu *vcpu);
- void (*flush_shadow_all)(struct kvm *kvm);
- /*
- * Must take care of flushing any cached GPA PTEs (e.g. guest entries in
- * VZ root TLB, or T&E GVA page tables and corresponding root TLB
- * mappings).
- */
- void (*flush_shadow_memslot)(struct kvm *kvm,
- const struct kvm_memory_slot *slot);
+ void (*prepare_flush_shadow)(struct kvm *kvm);
gpa_t (*gva_to_gpa)(gva_t gva);
void (*queue_timer_int)(struct kvm_vcpu *vcpu);
void (*dequeue_timer_int)(struct kvm_vcpu *vcpu);
diff --git a/arch/mips/kvm/mips.c b/arch/mips/kvm/mips.c
index 7db8234a4407..867b8de0fc07 100644
--- a/arch/mips/kvm/mips.c
+++ b/arch/mips/kvm/mips.c
@@ -206,7 +206,8 @@ void kvm_arch_flush_shadow_all(struct kvm *kvm)
kvm_mips_flush_gpa_pt(kvm, 0, ~0);

/* Let implementation do the rest */
- kvm_mips_callbacks->flush_shadow_all(kvm);
+ kvm_mips_callbacks->prepare_flush_shadow(kvm);
+ kvm_flush_remote_tlbs(kvm);
}

void kvm_arch_flush_shadow_memslot(struct kvm *kvm,
@@ -221,8 +222,7 @@ void kvm_arch_flush_shadow_memslot(struct kvm *kvm,
/* Flush slot from GPA */
kvm_mips_flush_gpa_pt(kvm, slot->base_gfn,
slot->base_gfn + slot->npages - 1);
- /* Let implementation do the rest */
- kvm_mips_callbacks->flush_shadow_memslot(kvm, slot);
+ kvm_arch_flush_remote_tlbs_memslot(kvm, slot);
spin_unlock(&kvm->mmu_lock);
}

@@ -262,9 +262,8 @@ void kvm_arch_commit_memory_region(struct kvm *kvm,
/* Write protect GPA page table entries */
needs_flush = kvm_mips_mkclean_gpa_pt(kvm, new->base_gfn,
new->base_gfn + new->npages - 1);
- /* Let implementation do the rest */
if (needs_flush)
- kvm_mips_callbacks->flush_shadow_memslot(kvm, new);
+ kvm_arch_flush_remote_tlbs_memslot(kvm, new);
spin_unlock(&kvm->mmu_lock);
}
}
@@ -1000,7 +999,8 @@ void kvm_arch_flush_remote_tlbs_memslot(struct kvm *kvm,
const struct kvm_memory_slot *memslot)
{
/* Let implementation handle TLB/GVA invalidation */
- kvm_mips_callbacks->flush_shadow_memslot(kvm, memslot);
+ kvm_mips_callbacks->prepare_flush_shadow(kvm);
+ kvm_flush_remote_tlbs(kvm);
}

long kvm_arch_vm_ioctl(struct file *filp, unsigned int ioctl, unsigned long arg)
diff --git a/arch/mips/kvm/mmu.c b/arch/mips/kvm/mmu.c
index 3dabeda82458..7e055e5dfd3c 100644
--- a/arch/mips/kvm/mmu.c
+++ b/arch/mips/kvm/mmu.c
@@ -491,7 +491,8 @@ int kvm_unmap_hva_range(struct kvm *kvm, unsigned long start, unsigned long end,
{
handle_hva_to_gpa(kvm, start, end, &kvm_unmap_hva_handler, NULL);

- kvm_mips_callbacks->flush_shadow_all(kvm);
+ kvm_mips_callbacks->prepare_flush_shadow(kvm);
+ kvm_flush_remote_tlbs(kvm);
return 0;
}

@@ -532,8 +533,10 @@ int kvm_set_spte_hva(struct kvm *kvm, unsigned long hva, pte_t pte)
int ret;

ret = handle_hva_to_gpa(kvm, hva, end, &kvm_set_spte_handler, &pte);
- if (ret)
- kvm_mips_callbacks->flush_shadow_all(kvm);
+ if (ret) {
+ kvm_mips_callbacks->prepare_flush_shadow(kvm);
+ kvm_flush_remote_tlbs(kvm);
+ }
return 0;
}

diff --git a/arch/mips/kvm/trap_emul.c b/arch/mips/kvm/trap_emul.c
index 0788c00d7e94..5f2df497599c 100644
--- a/arch/mips/kvm/trap_emul.c
+++ b/arch/mips/kvm/trap_emul.c
@@ -687,16 +687,8 @@ static int kvm_trap_emul_vcpu_setup(struct kvm_vcpu *vcpu)
return 0;
}

-static void kvm_trap_emul_flush_shadow_all(struct kvm *kvm)
+static void kvm_trap_emul_prepare_flush_shadow(struct kvm *kvm)
{
- /* Flush GVA page tables and invalidate GVA ASIDs on all VCPUs */
- kvm_flush_remote_tlbs(kvm);
-}
-
-static void kvm_trap_emul_flush_shadow_memslot(struct kvm *kvm,
- const struct kvm_memory_slot *slot)
-{
- kvm_trap_emul_flush_shadow_all(kvm);
}

static u64 kvm_trap_emul_get_one_regs[] = {
@@ -1280,8 +1272,7 @@ static struct kvm_mips_callbacks kvm_trap_emul_callbacks = {
.vcpu_init = kvm_trap_emul_vcpu_init,
.vcpu_uninit = kvm_trap_emul_vcpu_uninit,
.vcpu_setup = kvm_trap_emul_vcpu_setup,
- .flush_shadow_all = kvm_trap_emul_flush_shadow_all,
- .flush_shadow_memslot = kvm_trap_emul_flush_shadow_memslot,
+ .prepare_flush_shadow = kvm_trap_emul_prepare_flush_shadow,
.gva_to_gpa = kvm_trap_emul_gva_to_gpa_cb,
.queue_timer_int = kvm_mips_queue_timer_int_cb,
.dequeue_timer_int = kvm_mips_dequeue_timer_int_cb,
diff --git a/arch/mips/kvm/vz.c b/arch/mips/kvm/vz.c
index 2ffbe9264a31..2c75571dc4a2 100644
--- a/arch/mips/kvm/vz.c
+++ b/arch/mips/kvm/vz.c
@@ -3211,32 +3211,22 @@ static int kvm_vz_vcpu_setup(struct kvm_vcpu *vcpu)
return 0;
}

-static void kvm_vz_flush_shadow_all(struct kvm *kvm)
+static void kvm_vz_prepare_flush_shadow(struct kvm *kvm)
{
- if (cpu_has_guestid) {
- /* Flush GuestID for each VCPU individually */
- kvm_flush_remote_tlbs(kvm);
- } else {
+ if (!cpu_has_guestid) {
/*
* For each CPU there is a single GPA ASID used by all VCPUs in
* the VM, so it doesn't make sense for the VCPUs to handle
* invalidation of these ASIDs individually.
*
* Instead mark all CPUs as needing ASID invalidation in
- * asid_flush_mask, and just use kvm_flush_remote_tlbs(kvm) to
+ * asid_flush_mask, and kvm_flush_remote_tlbs(kvm) will
* kick any running VCPUs so they check asid_flush_mask.
*/
cpumask_setall(&kvm->arch.asid_flush_mask);
- kvm_flush_remote_tlbs(kvm);
}
}

-static void kvm_vz_flush_shadow_memslot(struct kvm *kvm,
- const struct kvm_memory_slot *slot)
-{
- kvm_vz_flush_shadow_all(kvm);
-}
-
static void kvm_vz_vcpu_reenter(struct kvm_vcpu *vcpu)
{
int cpu = smp_processor_id();
@@ -3292,8 +3282,7 @@ static struct kvm_mips_callbacks kvm_vz_callbacks = {
.vcpu_init = kvm_vz_vcpu_init,
.vcpu_uninit = kvm_vz_vcpu_uninit,
.vcpu_setup = kvm_vz_vcpu_setup,
- .flush_shadow_all = kvm_vz_flush_shadow_all,
- .flush_shadow_memslot = kvm_vz_flush_shadow_memslot,
+ .prepare_flush_shadow = kvm_vz_prepare_flush_shadow,
.gva_to_gpa = kvm_vz_gva_to_gpa_cb,
.queue_timer_int = kvm_vz_queue_timer_int_cb,
.dequeue_timer_int = kvm_vz_dequeue_timer_int_cb,
--
2.30.1