linux-kernel - [PATCH 10/16] KVM: Use gfn_to_pfn_cache's immutable "kvm" in kvm_gpc

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Date:   Thu, 27 Oct 2022 12:18:43 -0400
From:   Paolo Bonzini <pbonzini@...hat.com>
To:     linux-kernel@...r.kernel.org, kvm@...r.kernel.org
Cc:     mhal@...x.co, seanjc@...gle.com
Subject: [PATCH 10/16] KVM: Use gfn_to_pfn_cache's immutable "kvm" in kvm_gpc_refresh()

From: Michal Luczaj <mhal@...x.co>

Make kvm_gpc_refresh() use kvm instance cached in gfn_to_pfn_cache.

No functional change intended.

Suggested-by: Sean Christopherson <seanjc@...gle.com>
Signed-off-by: Michal Luczaj <mhal@...x.co>
[sean: leave kvm_gpc_unmap() as-is]
Signed-off-by: Sean Christopherson <seanjc@...gle.com>
Message-Id: <20221013211234.1318131-11-seanjc@...gle.com>
Signed-off-by: Paolo Bonzini <pbonzini@...hat.com>
---
 arch/x86/kvm/x86.c       |  2 +-
 arch/x86/kvm/xen.c       |  8 ++++----
 include/linux/kvm_host.h |  8 +++-----
 virt/kvm/pfncache.c      | 11 +++++------
 4 files changed, 13 insertions(+), 16 deletions(-)

diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index 0e3546aa34dd..bdc3110650d3 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -3037,7 +3037,7 @@ static void kvm_setup_guest_pvclock(struct kvm_vcpu *v,
 	while (!kvm_gpc_check(gpc, gpc->gpa)) {
 		read_unlock_irqrestore(&gpc->lock, flags);
 
-		if (kvm_gpc_refresh(v->kvm, gpc, gpc->gpa))
+		if (kvm_gpc_refresh(gpc, gpc->gpa))
 			return;
 
 		read_lock_irqsave(&gpc->lock, flags);
diff --git a/arch/x86/kvm/xen.c b/arch/x86/kvm/xen.c
index d3cb28388e3c..545ecbd0ca36 100644
--- a/arch/x86/kvm/xen.c
+++ b/arch/x86/kvm/xen.c
@@ -248,7 +248,7 @@ void kvm_xen_update_runstate_guest(struct kvm_vcpu *v, int state)
 		if (state == RUNSTATE_runnable)
 			return;
 
-		if (kvm_gpc_refresh(v->kvm, gpc, gpc->gpa))
+		if (kvm_gpc_refresh(gpc, gpc->gpa))
 			return;
 
 		read_lock_irqsave(&gpc->lock, flags);
@@ -377,7 +377,7 @@ void kvm_xen_inject_pending_events(struct kvm_vcpu *v)
 	while (!kvm_gpc_check(gpc, gpc->gpa)) {
 		read_unlock_irqrestore(&gpc->lock, flags);
 
-		if (kvm_gpc_refresh(v->kvm, gpc, gpc->gpa))
+		if (kvm_gpc_refresh(gpc, gpc->gpa))
 			return;
 
 		read_lock_irqsave(&gpc->lock, flags);
@@ -451,7 +451,7 @@ int __kvm_xen_has_interrupt(struct kvm_vcpu *v)
 		if (in_atomic() || !task_is_running(current))
 			return 1;
 
-		if (kvm_gpc_refresh(v->kvm, gpc, gpc->gpa)) {
+		if (kvm_gpc_refresh(gpc, gpc->gpa)) {
 			/*
 			 * If this failed, userspace has screwed up the
 			 * vcpu_info mapping. No interrupts for you.
@@ -1504,7 +1504,7 @@ static int kvm_xen_set_evtchn(struct kvm_xen_evtchn *xe, struct kvm *kvm)
 			break;
 
 		idx = srcu_read_lock(&kvm->srcu);
-		rc = kvm_gpc_refresh(kvm, gpc, gpc->gpa);
+		rc = kvm_gpc_refresh(gpc, gpc->gpa);
 		srcu_read_unlock(&kvm->srcu, idx);
 	} while(!rc);
 
diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h
index 466988b8b5f6..d4a49c89bc08 100644
--- a/include/linux/kvm_host.h
+++ b/include/linux/kvm_host.h
@@ -1299,22 +1299,20 @@ bool kvm_gpc_check(struct gfn_to_pfn_cache *gpc, gpa_t gpa);
 /**
  * kvm_gpc_refresh - update a previously initialized cache.
  *
- * @kvm:	   pointer to kvm instance.
  * @gpc:	   struct gfn_to_pfn_cache object.
  * @gpa:	   updated 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 will attempt to refresh a gfn_to_pfn_cache. Note that a successful
- * returm from this function does not mean the page can be immediately
+ * return from this function does not mean the page can be immediately
  * accessed because it may have raced with an invalidation. Callers must
  * still lock and check the cache status, as this function does not return
  * with the lock still held to permit access.
  */
-int kvm_gpc_refresh(struct kvm *kvm, struct gfn_to_pfn_cache *gpc, gpa_t gpa);
+int kvm_gpc_refresh(struct gfn_to_pfn_cache *gpc, gpa_t gpa);
 
 /**
  * kvm_gpc_unmap - temporarily unmap a gfn_to_pfn_cache.
diff --git a/virt/kvm/pfncache.c b/virt/kvm/pfncache.c
index 48f400819d1e..e4ebea75dca9 100644
--- a/virt/kvm/pfncache.c
+++ b/virt/kvm/pfncache.c
@@ -237,10 +237,9 @@ static kvm_pfn_t hva_to_pfn_retry(struct gfn_to_pfn_cache *gpc)
 	return -EFAULT;
 }
 
-static int __kvm_gpc_refresh(struct kvm *kvm, struct gfn_to_pfn_cache *gpc, gpa_t gpa,
-			     unsigned long len)
+static int __kvm_gpc_refresh(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);
 	unsigned long page_offset = gpa & ~PAGE_MASK;
 	bool unmap_old = false;
 	unsigned long old_uhva;
@@ -330,9 +329,9 @@ static int __kvm_gpc_refresh(struct kvm *kvm, struct gfn_to_pfn_cache *gpc, gpa_
 	return ret;
 }
 
-int kvm_gpc_refresh(struct kvm *kvm, struct gfn_to_pfn_cache *gpc, gpa_t gpa)
+int kvm_gpc_refresh(struct gfn_to_pfn_cache *gpc, gpa_t gpa)
 {
-	return __kvm_gpc_refresh(kvm, gpc, gpa, gpc->len);
+	return __kvm_gpc_refresh(gpc, gpa, gpc->len);
 }
 EXPORT_SYMBOL_GPL(kvm_gpc_refresh);
 
@@ -401,7 +400,7 @@ int kvm_gpc_activate(struct gfn_to_pfn_cache *gpc, gpa_t gpa, unsigned long len)
 		gpc->active = true;
 		write_unlock_irq(&gpc->lock);
 	}
-	return __kvm_gpc_refresh(kvm, gpc, gpa, len);
+	return __kvm_gpc_refresh(gpc, gpa, len);
 }
 EXPORT_SYMBOL_GPL(kvm_gpc_activate);
 
-- 
2.31.1