All of lore.kernel.org
 help / color / mirror / Atom feed
From: Marc Zyngier <maz@kernel.org>
To: kvmarm@lists.cs.columbia.edu, kvm@vger.kernel.org
Cc: will@kernel.org, catalin.marinas@arm.com, andrew.jones@linux.dev,
	shan.gavin@gmail.com, bgardon@google.com, dmatlack@google.com,
	pbonzini@redhat.com, zhenyzha@redhat.com, shuah@kernel.org
Subject: [PATCH v2 5/6] KVM: selftests: dirty-log: Upgrade flag accesses to acquire/release semantics
Date: Mon, 26 Sep 2022 15:51:19 +0100	[thread overview]
Message-ID: <20220926145120.27974-6-maz@kernel.org> (raw)
In-Reply-To: <20220926145120.27974-1-maz@kernel.org>

In order to preserve ordering, make sure that the flag accesses
in the dirty log are done using acquire/release accessors.

Signed-off-by: Marc Zyngier <maz@kernel.org>
---
 tools/testing/selftests/kvm/dirty_log_test.c | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/tools/testing/selftests/kvm/dirty_log_test.c b/tools/testing/selftests/kvm/dirty_log_test.c
index 9c883c94d478..53627add8a7c 100644
--- a/tools/testing/selftests/kvm/dirty_log_test.c
+++ b/tools/testing/selftests/kvm/dirty_log_test.c
@@ -17,6 +17,7 @@
 #include <linux/bitmap.h>
 #include <linux/bitops.h>
 #include <linux/atomic.h>
+#include <asm/barrier.h>
 
 #include "kvm_util.h"
 #include "test_util.h"
@@ -279,12 +280,12 @@ static void dirty_ring_create_vm_done(struct kvm_vm *vm)
 
 static inline bool dirty_gfn_is_dirtied(struct kvm_dirty_gfn *gfn)
 {
-	return gfn->flags == KVM_DIRTY_GFN_F_DIRTY;
+	return smp_load_acquire(&gfn->flags) == KVM_DIRTY_GFN_F_DIRTY;
 }
 
 static inline void dirty_gfn_set_collected(struct kvm_dirty_gfn *gfn)
 {
-	gfn->flags = KVM_DIRTY_GFN_F_RESET;
+	smp_store_release(&gfn->flags, KVM_DIRTY_GFN_F_RESET);
 }
 
 static uint32_t dirty_ring_collect_one(struct kvm_dirty_gfn *dirty_gfns,
-- 
2.34.1

_______________________________________________
kvmarm mailing list
kvmarm@lists.cs.columbia.edu
https://lists.cs.columbia.edu/mailman/listinfo/kvmarm

WARNING: multiple messages have this Message-ID (diff)
From: Marc Zyngier <maz@kernel.org>
To: kvmarm@lists.cs.columbia.edu, kvm@vger.kernel.org
Cc: catalin.marinas@arm.com, bgardon@google.com, shuah@kernel.org,
	andrew.jones@linux.dev, will@kernel.org, dmatlack@google.com,
	peterx@redhat.com, pbonzini@redhat.com, zhenyzha@redhat.com,
	shan.gavin@gmail.com, gshan@redhat.com,
	James Morse <james.morse@arm.com>,
	Suzuki K Poulose <suzuki.poulose@arm.com>,
	Alexandru Elisei <alexandru.elisei@arm.com>,
	Oliver Upton <oliver.upton@linux.dev>
Subject: [PATCH v2 5/6] KVM: selftests: dirty-log: Upgrade flag accesses to acquire/release semantics
Date: Mon, 26 Sep 2022 15:51:19 +0100	[thread overview]
Message-ID: <20220926145120.27974-6-maz@kernel.org> (raw)
In-Reply-To: <20220926145120.27974-1-maz@kernel.org>

In order to preserve ordering, make sure that the flag accesses
in the dirty log are done using acquire/release accessors.

Signed-off-by: Marc Zyngier <maz@kernel.org>
---
 tools/testing/selftests/kvm/dirty_log_test.c | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/tools/testing/selftests/kvm/dirty_log_test.c b/tools/testing/selftests/kvm/dirty_log_test.c
index 9c883c94d478..53627add8a7c 100644
--- a/tools/testing/selftests/kvm/dirty_log_test.c
+++ b/tools/testing/selftests/kvm/dirty_log_test.c
@@ -17,6 +17,7 @@
 #include <linux/bitmap.h>
 #include <linux/bitops.h>
 #include <linux/atomic.h>
+#include <asm/barrier.h>
 
 #include "kvm_util.h"
 #include "test_util.h"
@@ -279,12 +280,12 @@ static void dirty_ring_create_vm_done(struct kvm_vm *vm)
 
 static inline bool dirty_gfn_is_dirtied(struct kvm_dirty_gfn *gfn)
 {
-	return gfn->flags == KVM_DIRTY_GFN_F_DIRTY;
+	return smp_load_acquire(&gfn->flags) == KVM_DIRTY_GFN_F_DIRTY;
 }
 
 static inline void dirty_gfn_set_collected(struct kvm_dirty_gfn *gfn)
 {
-	gfn->flags = KVM_DIRTY_GFN_F_RESET;
+	smp_store_release(&gfn->flags, KVM_DIRTY_GFN_F_RESET);
 }
 
 static uint32_t dirty_ring_collect_one(struct kvm_dirty_gfn *dirty_gfns,
-- 
2.34.1


  parent reply	other threads:[~2022-09-26 14:51 UTC|newest]

Thread overview: 20+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2022-09-26 14:51 [PATCH v2 0/6] KVM: Fix dirty-ring ordering on weakly ordered architectures Marc Zyngier
2022-09-26 14:51 ` Marc Zyngier
2022-09-26 14:51 ` [PATCH v2 1/6] KVM: Use acquire/release semantics when accessing dirty ring GFN state Marc Zyngier
2022-09-26 14:51   ` Marc Zyngier
2022-09-26 14:51 ` [PATCH v2 2/6] KVM: Add KVM_CAP_DIRTY_LOG_RING_ACQ_REL capability and config option Marc Zyngier
2022-09-26 14:51   ` Marc Zyngier
2022-09-26 14:51 ` [PATCH v2 3/6] KVM: x86: Select CONFIG_HAVE_KVM_DIRTY_RING_ACQ_REL Marc Zyngier
2022-09-26 14:51   ` Marc Zyngier
2022-09-26 14:51 ` [PATCH v2 4/6] KVM: Document weakly ordered architecture requirements for dirty ring Marc Zyngier
2022-09-26 14:51   ` Marc Zyngier
2022-09-26 14:51 ` Marc Zyngier [this message]
2022-09-26 14:51   ` [PATCH v2 5/6] KVM: selftests: dirty-log: Upgrade flag accesses to acquire/release semantics Marc Zyngier
2022-09-26 14:51 ` [PATCH v2 6/6] KVM: selftests: dirty-log: Use KVM_CAP_DIRTY_LOG_RING_ACQ_REL if available Marc Zyngier
2022-09-26 14:51   ` Marc Zyngier
2022-09-27  0:58 ` [PATCH v2 0/6] KVM: Fix dirty-ring ordering on weakly ordered architectures Gavin Shan
2022-09-27  0:58   ` Gavin Shan
2022-09-27 15:54 ` Peter Xu
2022-09-27 15:54   ` Peter Xu
2022-09-29  9:58 ` Marc Zyngier
2022-09-29  9:58   ` Marc Zyngier

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20220926145120.27974-6-maz@kernel.org \
    --to=maz@kernel.org \
    --cc=andrew.jones@linux.dev \
    --cc=bgardon@google.com \
    --cc=catalin.marinas@arm.com \
    --cc=dmatlack@google.com \
    --cc=kvm@vger.kernel.org \
    --cc=kvmarm@lists.cs.columbia.edu \
    --cc=pbonzini@redhat.com \
    --cc=shan.gavin@gmail.com \
    --cc=shuah@kernel.org \
    --cc=will@kernel.org \
    --cc=zhenyzha@redhat.com \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body. 
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.