Commit e308c24a authored by Michal Luczaj's avatar Michal Luczaj Committed by David Woodhouse
Browse files

KVM: Use gfn_to_pfn_cache's immutable "kvm" in kvm_gpc_check() 



Make kvm_gpc_check() use kvm instance cached in gfn_to_pfn_cache.

Suggested-by: default avatarSean Christopherson <seanjc@google.com>
Signed-off-by: default avatarMichal Luczaj <mhal@rbox.co>
Signed-off-by: default avatarSean Christopherson <seanjc@google.com>
Signed-off-by: default avatarDavid Woodhouse <dwmw@amazon.co.uk>
parent 8c82a0b3

arch/x86/kvm/x86.c

+1 −1
Original line number Diff line number Diff line
@@ -3035,7 +3035,7 @@ static void kvm_setup_guest_pvclock(struct kvm_vcpu *v, 
	unsigned long flags;



	read_lock_irqsave(&gpc->lock, flags);

	while (!kvm_gpc_check(v->kvm, gpc, gpc->gpa,

	while (!kvm_gpc_check(gpc, gpc->gpa,

			      offset + sizeof(*guest_hv_clock))) {

		read_unlock_irqrestore(&gpc->lock, flags);

arch/x86/kvm/xen.c

+7 −9
Original line number Diff line number Diff line
@@ -272,7 +272,7 @@ static void kvm_xen_update_runstate_guest(struct kvm_vcpu *v, bool atomic) 
	 * gfn_to_pfn caches that cover the region.

	 */

	read_lock_irqsave(&gpc1->lock, flags);

	while (!kvm_gpc_check(v->kvm, gpc1, gpc1->gpa, user_len1)) {

	while (!kvm_gpc_check(gpc1, gpc1->gpa, user_len1)) {

		read_unlock_irqrestore(&gpc1->lock, flags);



		/* When invoked from kvm_sched_out() we cannot sleep */
@@ -308,7 +308,7 @@ static void kvm_xen_update_runstate_guest(struct kvm_vcpu *v, bool atomic) 
		 */

		read_lock(&gpc2->lock);



		if (!kvm_gpc_check(v->kvm, gpc2, gpc2->gpa, user_len2)) {

		if (!kvm_gpc_check(gpc2, gpc2->gpa, user_len2)) {

			read_unlock(&gpc2->lock);

			read_unlock_irqrestore(&gpc1->lock, flags);
@@ -488,8 +488,7 @@ void kvm_xen_inject_pending_events(struct kvm_vcpu *v) 
	 * little more honest about it.

	 */

	read_lock_irqsave(&gpc->lock, flags);

	while (!kvm_gpc_check(v->kvm, gpc, gpc->gpa,

			      sizeof(struct vcpu_info))) {

	while (!kvm_gpc_check(gpc, gpc->gpa, sizeof(struct vcpu_info))) {

		read_unlock_irqrestore(&gpc->lock, flags);



		if (kvm_gpc_refresh(v->kvm, gpc, gpc->gpa,
@@ -553,8 +552,7 @@ int __kvm_xen_has_interrupt(struct kvm_vcpu *v) 
		     sizeof_field(struct compat_vcpu_info, evtchn_upcall_pending));



	read_lock_irqsave(&gpc->lock, flags);

	while (!kvm_gpc_check(v->kvm, gpc, gpc->gpa,

			      sizeof(struct vcpu_info))) {

	while (!kvm_gpc_check(gpc, gpc->gpa, sizeof(struct vcpu_info))) {

		read_unlock_irqrestore(&gpc->lock, flags);



		/*
@@ -1158,7 +1156,7 @@ static bool wait_pending_event(struct kvm_vcpu *vcpu, int nr_ports, 


	read_lock_irqsave(&gpc->lock, flags);

	idx = srcu_read_lock(&kvm->srcu);

	if (!kvm_gpc_check(kvm, gpc, gpc->gpa, PAGE_SIZE))

	if (!kvm_gpc_check(gpc, gpc->gpa, PAGE_SIZE))

		goto out_rcu;



	ret = false;
@@ -1580,7 +1578,7 @@ int kvm_xen_set_evtchn_fast(struct kvm_xen_evtchn *xe, struct kvm *kvm) 
	idx = srcu_read_lock(&kvm->srcu);



	read_lock_irqsave(&gpc->lock, flags);

	if (!kvm_gpc_check(kvm, gpc, gpc->gpa, PAGE_SIZE))

	if (!kvm_gpc_check(gpc, gpc->gpa, PAGE_SIZE))

		goto out_rcu;



	if (IS_ENABLED(CONFIG_64BIT) && kvm->arch.xen.long_mode) {
@@ -1614,7 +1612,7 @@ int kvm_xen_set_evtchn_fast(struct kvm_xen_evtchn *xe, struct kvm *kvm) 
		gpc = &vcpu->arch.xen.vcpu_info_cache;



		read_lock_irqsave(&gpc->lock, flags);

		if (!kvm_gpc_check(kvm, gpc, gpc->gpa, sizeof(struct vcpu_info))) {

		if (!kvm_gpc_check(gpc, gpc->gpa, sizeof(struct vcpu_info))) {

			/*

			 * Could not access the vcpu_info. Set the bit in-kernel

			 * and prod the vCPU to deliver it for itself.

include/linux/kvm_host.h

+1 −3
Original line number Diff line number Diff line
@@ -1298,7 +1298,6 @@ 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.

 *

 * @kvm:	   pointer to kvm instance.

 * @gpc:	   struct gfn_to_pfn_cache object.

 * @gpa:	   current guest physical address to map.

 * @len:	   sanity check; the range being access must fit a single page.
@@ -1313,8 +1312,7 @@ int kvm_gpc_activate(struct gfn_to_pfn_cache *gpc, gpa_t gpa, unsigned long len) 
 * Callers in IN_GUEST_MODE may do so without locking, although they should

 * still hold a read lock on kvm->scru for the memslot checks.

 */

bool kvm_gpc_check(struct kvm *kvm, struct gfn_to_pfn_cache *gpc, gpa_t gpa,

		   unsigned long len);

bool kvm_gpc_check(struct gfn_to_pfn_cache *gpc, gpa_t gpa, unsigned long len);



/**

 * kvm_gpc_refresh - update a previously initialized cache.

virt/kvm/pfncache.c

+2 −3
Original line number Diff line number Diff line
@@ -76,10 +76,9 @@ void gfn_to_pfn_cache_invalidate_start(struct kvm *kvm, unsigned long start, 
	}

}



bool kvm_gpc_check(struct kvm *kvm, struct gfn_to_pfn_cache *gpc, gpa_t gpa,

		   unsigned long len)

bool kvm_gpc_check(struct gfn_to_pfn_cache *gpc, gpa_t gpa, unsigned long len)

{

	struct kvm_memslots *slots = kvm_memslots(kvm);

	struct kvm_memslots *slots = kvm_memslots(gpc->kvm);



	if (!gpc->active)

		return false;