From: Oliver Upton <oliver.upton@linux.dev>
To: Marc Zyngier <maz@kernel.org>, James Morse <james.morse@arm.com>,
Alexandru Elisei <alexandru.elisei@arm.com>,
Suzuki K Poulose <suzuki.poulose@arm.com>,
Oliver Upton <oliver.upton@linux.dev>,
Catalin Marinas <catalin.marinas@arm.com>,
Will Deacon <will@kernel.org>
Cc: linux-arm-kernel@lists.infradead.org,
kvmarm@lists.cs.columbia.edu, kvm@vger.kernel.org,
kvmarm@lists.linux.dev, linux-kernel@vger.kernel.org
Subject: [PATCH 3/4] KVM: arm64: Handle access faults behind the read lock
Date: Tue, 29 Nov 2022 19:19:45 +0000 [thread overview]
Message-ID: <20221129191946.1735662-4-oliver.upton@linux.dev> (raw)
In-Reply-To: <20221129191946.1735662-1-oliver.upton@linux.dev>
As the underlying software walkers are able to traverse and update
stage-2 in parallel there is no need to serialize access faults.
Only take the read lock when handling an access fault.
Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
---
arch/arm64/kvm/hyp/pgtable.c | 2 +-
arch/arm64/kvm/mmu.c | 4 ++--
2 files changed, 3 insertions(+), 3 deletions(-)
diff --git a/arch/arm64/kvm/hyp/pgtable.c b/arch/arm64/kvm/hyp/pgtable.c
index 9626f615d9b8..1a3dd9774707 100644
--- a/arch/arm64/kvm/hyp/pgtable.c
+++ b/arch/arm64/kvm/hyp/pgtable.c
@@ -1097,7 +1097,7 @@ kvm_pte_t kvm_pgtable_stage2_mkyoung(struct kvm_pgtable *pgt, u64 addr)
int ret;
ret = stage2_update_leaf_attrs(pgt, addr, 1, KVM_PTE_LEAF_ATTR_LO_S2_AF, 0,
- &pte, NULL, 0);
+ &pte, NULL, KVM_PGTABLE_WALK_SHARED);
if (!ret)
dsb(ishst);
diff --git a/arch/arm64/kvm/mmu.c b/arch/arm64/kvm/mmu.c
index 886ad5ee767a..347985a56414 100644
--- a/arch/arm64/kvm/mmu.c
+++ b/arch/arm64/kvm/mmu.c
@@ -1404,10 +1404,10 @@ static void handle_access_fault(struct kvm_vcpu *vcpu, phys_addr_t fault_ipa)
trace_kvm_access_fault(fault_ipa);
- write_lock(&vcpu->kvm->mmu_lock);
+ read_lock(&vcpu->kvm->mmu_lock);
mmu = vcpu->arch.hw_mmu;
pte = kvm_pgtable_stage2_mkyoung(mmu->pgt, fault_ipa);
- write_unlock(&vcpu->kvm->mmu_lock);
+ read_unlock(&vcpu->kvm->mmu_lock);
if (kvm_pte_valid(pte))
kvm_set_pfn_accessed(kvm_pte_to_pfn(pte));
--
2.38.1.584.g0f3c55d4c2-goog
_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
next prev parent reply other threads:[~2022-11-29 19:24 UTC|newest]
Thread overview: 13+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-11-29 19:19 [PATCH 0/4] KVM: arm64: Parallel access faults Oliver Upton
2022-11-29 19:19 ` [PATCH 1/4] KVM: arm64: Use KVM's pte type/helpers in handle_access_fault() Oliver Upton
2022-11-29 19:19 ` [PATCH 2/4] KVM: arm64: Don't serialize if the access flag isn't set Oliver Upton
2022-11-29 20:52 ` Ricardo Koller
2022-11-29 21:15 ` Oliver Upton
2022-11-30 1:23 ` Ricardo Koller
2022-11-30 8:21 ` Marc Zyngier
2022-11-30 23:21 ` Ricardo Koller
2022-12-01 18:11 ` Oliver Upton
2022-11-29 19:19 ` Oliver Upton [this message]
2022-11-29 21:00 ` [PATCH 3/4] KVM: arm64: Handle access faults behind the read lock Ricardo Koller
2022-11-29 19:19 ` [PATCH 4/4] KVM: arm64: Condition HW AF updates on config option Oliver Upton
2022-11-30 16:54 ` [PATCH 0/4] KVM: arm64: Parallel access faults 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=20221129191946.1735662-4-oliver.upton@linux.dev \
--to=oliver.upton@linux.dev \
--cc=alexandru.elisei@arm.com \
--cc=catalin.marinas@arm.com \
--cc=james.morse@arm.com \
--cc=kvm@vger.kernel.org \
--cc=kvmarm@lists.cs.columbia.edu \
--cc=kvmarm@lists.linux.dev \
--cc=linux-arm-kernel@lists.infradead.org \
--cc=linux-kernel@vger.kernel.org \
--cc=maz@kernel.org \
--cc=suzuki.poulose@arm.com \
--cc=will@kernel.org \
/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 a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).