[PATCH v2 06/16] KVM: Store immutable gfn_to_pfn_cache properties

From: Sean Christopherson
Date: Thu Oct 13 2022 - 17:15:35 EST

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From: Michal Luczaj <mhal@xxxxxxx>

Move the assignment of immutable properties @kvm, @vcpu, and @usage to
the initializer. Make _activate() and _deactivate() use stored values.

Note, @len is also effectively immutable, but less obviously so. Leave
@len as is for now, it will be addressed in a future patch.

Suggested-by: Sean Christopherson <seanjc@xxxxxxxxxx>
Signed-off-by: Michal Luczaj <mhal@xxxxxxx>
[sean: handle @len in a separate patch]
Signed-off-by: Sean Christopherson <seanjc@xxxxxxxxxx>
---
arch/x86/kvm/x86.c | 14 +++++-------
arch/x86/kvm/xen.c | 47 ++++++++++++++++++---------------------
include/linux/kvm_host.h | 37 +++++++++++++++---------------
include/linux/kvm_types.h | 1 +
virt/kvm/pfncache.c | 22 +++++++++++-------
5 files changed, 61 insertions(+), 60 deletions(-)

diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index fd00e6a33203..9c68050672de 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -2314,13 +2314,11 @@ static void kvm_write_system_time(struct kvm_vcpu *vcpu, gpa_t system_time,
kvm_make_request(KVM_REQ_GLOBAL_CLOCK_UPDATE, vcpu);

/* we verify if the enable bit is set... */
- if (system_time & 1) {
- kvm_gpc_activate(vcpu->kvm, &vcpu->arch.pv_time, vcpu,
- KVM_HOST_USES_PFN, system_time & ~1ULL,
+ if (system_time & 1)
+ kvm_gpc_activate(&vcpu->arch.pv_time, system_time & ~1ULL,
sizeof(struct pvclock_vcpu_time_info));
- } else {
- kvm_gpc_deactivate(vcpu->kvm, &vcpu->arch.pv_time);
- }
+ else
+ kvm_gpc_deactivate(&vcpu->arch.pv_time);

return;
}
@@ -3388,7 +3386,7 @@ static int kvm_pv_enable_async_pf_int(struct kvm_vcpu *vcpu, u64 data)

static void kvmclock_reset(struct kvm_vcpu *vcpu)
{
- kvm_gpc_deactivate(vcpu->kvm, &vcpu->arch.pv_time);
+ kvm_gpc_deactivate(&vcpu->arch.pv_time);
vcpu->arch.time = 0;
}

@@ -11757,7 +11755,7 @@ int kvm_arch_vcpu_create(struct kvm_vcpu *vcpu)
vcpu->arch.regs_avail = ~0;
vcpu->arch.regs_dirty = ~0;

- kvm_gpc_init(&vcpu->arch.pv_time);
+ kvm_gpc_init(&vcpu->arch.pv_time, vcpu->kvm, vcpu, KVM_HOST_USES_PFN);

if (!irqchip_in_kernel(vcpu->kvm) || kvm_vcpu_is_reset_bsp(vcpu))
vcpu->arch.mp_state = KVM_MP_STATE_RUNNABLE;
diff --git a/arch/x86/kvm/xen.c b/arch/x86/kvm/xen.c
index 74d9f4985f93..55b7195d69d6 100644
--- a/arch/x86/kvm/xen.c
+++ b/arch/x86/kvm/xen.c
@@ -42,13 +42,12 @@ static int kvm_xen_shared_info_init(struct kvm *kvm, gfn_t gfn)
int idx = srcu_read_lock(&kvm->srcu);

if (gfn == GPA_INVALID) {
- kvm_gpc_deactivate(kvm, gpc);
+ kvm_gpc_deactivate(gpc);
goto out;
}

do {
- ret = kvm_gpc_activate(kvm, gpc, NULL, KVM_HOST_USES_PFN, gpa,
- PAGE_SIZE);
+ ret = kvm_gpc_activate(gpc, gpa, PAGE_SIZE);
if (ret)
goto out;

@@ -550,15 +549,13 @@ int kvm_xen_vcpu_set_attr(struct kvm_vcpu *vcpu, struct kvm_xen_vcpu_attr *data)
offsetof(struct compat_vcpu_info, time));

if (data->u.gpa == GPA_INVALID) {
- kvm_gpc_deactivate(vcpu->kvm, &vcpu->arch.xen.vcpu_info_cache);
+ kvm_gpc_deactivate(&vcpu->arch.xen.vcpu_info_cache);
r = 0;
break;
}

- r = kvm_gpc_activate(vcpu->kvm,
- &vcpu->arch.xen.vcpu_info_cache, NULL,
- KVM_HOST_USES_PFN, data->u.gpa,
- sizeof(struct vcpu_info));
+ r = kvm_gpc_activate(&vcpu->arch.xen.vcpu_info_cache,
+ data->u.gpa, sizeof(struct vcpu_info));
if (!r)
kvm_make_request(KVM_REQ_CLOCK_UPDATE, vcpu);

@@ -566,15 +563,13 @@ int kvm_xen_vcpu_set_attr(struct kvm_vcpu *vcpu, struct kvm_xen_vcpu_attr *data)

case KVM_XEN_VCPU_ATTR_TYPE_VCPU_TIME_INFO:
if (data->u.gpa == GPA_INVALID) {
- kvm_gpc_deactivate(vcpu->kvm,
- &vcpu->arch.xen.vcpu_time_info_cache);
+ kvm_gpc_deactivate(&vcpu->arch.xen.vcpu_time_info_cache);
r = 0;
break;
}

- r = kvm_gpc_activate(vcpu->kvm,
- &vcpu->arch.xen.vcpu_time_info_cache,
- NULL, KVM_HOST_USES_PFN, data->u.gpa,
+ r = kvm_gpc_activate(&vcpu->arch.xen.vcpu_time_info_cache,
+ data->u.gpa,
sizeof(struct pvclock_vcpu_time_info));
if (!r)
kvm_make_request(KVM_REQ_CLOCK_UPDATE, vcpu);
@@ -586,14 +581,13 @@ int kvm_xen_vcpu_set_attr(struct kvm_vcpu *vcpu, struct kvm_xen_vcpu_attr *data)
break;
}
if (data->u.gpa == GPA_INVALID) {
- kvm_gpc_deactivate(vcpu->kvm,
- &vcpu->arch.xen.runstate_cache);
+ kvm_gpc_deactivate(&vcpu->arch.xen.runstate_cache);
r = 0;
break;
}

- r = kvm_gpc_activate(vcpu->kvm, &vcpu->arch.xen.runstate_cache,
- NULL, KVM_HOST_USES_PFN, data->u.gpa,
+ r = kvm_gpc_activate(&vcpu->arch.xen.runstate_cache,
+ data->u.gpa,
sizeof(struct vcpu_runstate_info));
break;

@@ -1814,9 +1808,12 @@ void kvm_xen_init_vcpu(struct kvm_vcpu *vcpu)

timer_setup(&vcpu->arch.xen.poll_timer, cancel_evtchn_poll, 0);

- kvm_gpc_init(&vcpu->arch.xen.runstate_cache);
- kvm_gpc_init(&vcpu->arch.xen.vcpu_info_cache);
- kvm_gpc_init(&vcpu->arch.xen.vcpu_time_info_cache);
+ kvm_gpc_init(&vcpu->arch.xen.runstate_cache, vcpu->kvm, NULL,
+ KVM_HOST_USES_PFN);
+ kvm_gpc_init(&vcpu->arch.xen.vcpu_info_cache, vcpu->kvm, NULL,
+ KVM_HOST_USES_PFN);
+ kvm_gpc_init(&vcpu->arch.xen.vcpu_time_info_cache, vcpu->kvm, NULL,
+ KVM_HOST_USES_PFN);
}

void kvm_xen_destroy_vcpu(struct kvm_vcpu *vcpu)
@@ -1824,9 +1821,9 @@ void kvm_xen_destroy_vcpu(struct kvm_vcpu *vcpu)
if (kvm_xen_timer_enabled(vcpu))
kvm_xen_stop_timer(vcpu);

- kvm_gpc_deactivate(vcpu->kvm, &vcpu->arch.xen.runstate_cache);
- kvm_gpc_deactivate(vcpu->kvm, &vcpu->arch.xen.vcpu_info_cache);
- kvm_gpc_deactivate(vcpu->kvm, &vcpu->arch.xen.vcpu_time_info_cache);
+ kvm_gpc_deactivate(&vcpu->arch.xen.runstate_cache);
+ kvm_gpc_deactivate(&vcpu->arch.xen.vcpu_info_cache);
+ kvm_gpc_deactivate(&vcpu->arch.xen.vcpu_time_info_cache);

del_timer_sync(&vcpu->arch.xen.poll_timer);
}
@@ -1834,7 +1831,7 @@ void kvm_xen_destroy_vcpu(struct kvm_vcpu *vcpu)
void kvm_xen_init_vm(struct kvm *kvm)
{
idr_init(&kvm->arch.xen.evtchn_ports);
- kvm_gpc_init(&kvm->arch.xen.shinfo_cache);
+ kvm_gpc_init(&kvm->arch.xen.shinfo_cache, kvm, NULL, KVM_HOST_USES_PFN);
}

void kvm_xen_destroy_vm(struct kvm *kvm)
@@ -1842,7 +1839,7 @@ void kvm_xen_destroy_vm(struct kvm *kvm)
struct evtchnfd *evtchnfd;
int i;

- kvm_gpc_deactivate(kvm, &kvm->arch.xen.shinfo_cache);
+ kvm_gpc_deactivate(&kvm->arch.xen.shinfo_cache);

idr_for_each_entry(&kvm->arch.xen.evtchn_ports, evtchnfd, i) {
if (!evtchnfd->deliver.port.port)
diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h
index bb020ee3b2fe..e5e70607a5ef 100644
--- a/include/linux/kvm_host.h
+++ b/include/linux/kvm_host.h
@@ -1243,18 +1243,7 @@ void kvm_vcpu_mark_page_dirty(struct kvm_vcpu *vcpu, gfn_t gfn);
* kvm_gpc_init - initialize gfn_to_pfn_cache.
*
* @gpc: struct gfn_to_pfn_cache object.
- *
- * This sets up a gfn_to_pfn_cache by initializing locks. Note, the cache must
- * be zero-allocated (or zeroed by the caller before init).
- */
-void kvm_gpc_init(struct gfn_to_pfn_cache *gpc);
-
-/**
- * kvm_gpc_activate - prepare a cached kernel mapping and HPA for a given guest
- * physical address.
- *
* @kvm: pointer to kvm instance.
- * @gpc: struct gfn_to_pfn_cache object.
* @vcpu: vCPU to be used for marking pages dirty and to be woken on
* invalidation.
* @usage: indicates if the resulting host physical PFN is used while
@@ -1263,20 +1252,31 @@ void kvm_gpc_init(struct gfn_to_pfn_cache *gpc);
* changes!---will also force @vcpu to exit the guest and
* refresh the cache); and/or if the PFN used directly
* by KVM (and thus needs a kernel virtual mapping).
+ *
+ * This sets up a gfn_to_pfn_cache by initializing locks and assigning the
+ * immutable attributes. Note, the cache must be zero-allocated (or zeroed by
+ * the caller before init).
+ */
+void kvm_gpc_init(struct gfn_to_pfn_cache *gpc, struct kvm *kvm,
+ struct kvm_vcpu *vcpu, enum pfn_cache_usage usage);
+
+/**
+ * kvm_gpc_activate - prepare a cached kernel mapping and HPA for a given guest
+ * physical address.
+ *
+ * @gpc: struct gfn_to_pfn_cache object.
* @gpa: guest physical address to map.
* @len: sanity check; the range being access must fit a single page.
*
* @return: 0 for success.
* -EINVAL for a mapping which would cross a page boundary.
- * -EFAULT for an untranslatable guest physical address.
+ * -EFAULT for an untranslatable guest physical address.
*
- * This primes a gfn_to_pfn_cache and links it into the @kvm's list for
+ * This primes a gfn_to_pfn_cache and links it into the @gpc->kvm's list for
* invalidations to be processed. Callers are required to use kvm_gpc_check()
* to ensure that the cache is valid before accessing the target page.
*/
-int kvm_gpc_activate(struct kvm *kvm, struct gfn_to_pfn_cache *gpc,
- struct kvm_vcpu *vcpu, enum pfn_cache_usage usage,
- gpa_t gpa, unsigned long len);
+int kvm_gpc_activate(struct gfn_to_pfn_cache *gpc, gpa_t gpa, unsigned long len);

/**
* kvm_gpc_check - check validity of a gfn_to_pfn_cache.
@@ -1335,13 +1335,12 @@ void kvm_gpc_unmap(struct kvm *kvm, struct gfn_to_pfn_cache *gpc);
/**
* kvm_gpc_deactivate - deactivate and unlink a gfn_to_pfn_cache.
*
- * @kvm: pointer to kvm instance.
* @gpc: struct gfn_to_pfn_cache object.
*
- * This removes a cache from the @kvm's list to be processed on MMU notifier
+ * This removes a cache from the VM's list to be processed on MMU notifier
* invocation.
*/
-void kvm_gpc_deactivate(struct kvm *kvm, struct gfn_to_pfn_cache *gpc);
+void kvm_gpc_deactivate(struct gfn_to_pfn_cache *gpc);

void kvm_sigset_activate(struct kvm_vcpu *vcpu);
void kvm_sigset_deactivate(struct kvm_vcpu *vcpu);
diff --git a/include/linux/kvm_types.h b/include/linux/kvm_types.h
index 3ca3db020e0e..76de36e56cdf 100644
--- a/include/linux/kvm_types.h
+++ b/include/linux/kvm_types.h
@@ -67,6 +67,7 @@ struct gfn_to_pfn_cache {
gpa_t gpa;
unsigned long uhva;
struct kvm_memory_slot *memslot;
+ struct kvm *kvm;
struct kvm_vcpu *vcpu;
struct list_head list;
rwlock_t lock;
diff --git a/virt/kvm/pfncache.c b/virt/kvm/pfncache.c
index 32ccf168361b..6756dfa60d5a 100644
--- a/virt/kvm/pfncache.c
+++ b/virt/kvm/pfncache.c
@@ -357,25 +357,29 @@ void kvm_gpc_unmap(struct kvm *kvm, struct gfn_to_pfn_cache *gpc)
}
EXPORT_SYMBOL_GPL(kvm_gpc_unmap);

-void kvm_gpc_init(struct gfn_to_pfn_cache *gpc)
+void kvm_gpc_init(struct gfn_to_pfn_cache *gpc, struct kvm *kvm,
+ struct kvm_vcpu *vcpu, enum pfn_cache_usage usage)
{
+ WARN_ON_ONCE(!usage || (usage & KVM_GUEST_AND_HOST_USE_PFN) != usage);
+ WARN_ON_ONCE((usage & KVM_GUEST_USES_PFN) && !vcpu);
+
rwlock_init(&gpc->lock);
mutex_init(&gpc->refresh_lock);
+
+ gpc->kvm = kvm;
+ gpc->vcpu = vcpu;
+ gpc->usage = usage;
}
EXPORT_SYMBOL_GPL(kvm_gpc_init);

-int kvm_gpc_activate(struct kvm *kvm, struct gfn_to_pfn_cache *gpc,
- struct kvm_vcpu *vcpu, enum pfn_cache_usage usage,
- gpa_t gpa, unsigned long len)
+int kvm_gpc_activate(struct gfn_to_pfn_cache *gpc, gpa_t gpa, unsigned long len)
{
- WARN_ON_ONCE(!usage || (usage & KVM_GUEST_AND_HOST_USE_PFN) != usage);
+ struct kvm *kvm = gpc->kvm;

if (!gpc->active) {
gpc->khva = NULL;
gpc->pfn = KVM_PFN_ERR_FAULT;
gpc->uhva = KVM_HVA_ERR_BAD;
- gpc->vcpu = vcpu;
- gpc->usage = usage;
gpc->valid = false;

spin_lock(&kvm->gpc_lock);
@@ -395,8 +399,10 @@ int kvm_gpc_activate(struct kvm *kvm, struct gfn_to_pfn_cache *gpc,
}
EXPORT_SYMBOL_GPL(kvm_gpc_activate);

-void kvm_gpc_deactivate(struct kvm *kvm, struct gfn_to_pfn_cache *gpc)
+void kvm_gpc_deactivate(struct gfn_to_pfn_cache *gpc)
{
+ struct kvm *kvm = gpc->kvm;
+
if (gpc->active) {
/*
* Deactivate the cache before removing it from the list, KVM
--
2.38.0.413.g74048e4d9e-goog

Next message: Justin Forbes: "Re: [PATCH 6.0 00/34] 6.0.2-rc1 review"
Previous message: Sean Christopherson: "[PATCH v2 16/16] KVM: selftests: Mark "guest_saw_irq" as volatile in xen_shinfo_test"
In reply to: Sean Christopherson: "[PATCH v2 16/16] KVM: selftests: Mark "guest_saw_irq" as volatile in xen_shinfo_test"
Messages sorted by: [ date ] [ thread ] [ subject ] [ author ]