From:   Gavin Shan <gshan@redhat.com>
To:     kvm@vger.kernel.org, linux-doc@vger.kernel.org,
        linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org,
        kvmarm@lists.linux.dev, kvmarm@lists.cs.columbia.edu
Cc:     pbonzini@redhat.com, corbet@lwn.net, maz@kernel.org,
        james.morse@arm.com, suzuki.poulose@arm.com,
        oliver.upton@linux.dev, yuzenghui@huawei.com,
        catalin.marinas@arm.com, will@kernel.org, yuzhe@nfschina.com,
        gshan@redhat.com, seanjc@google.com, isaku.yamahata@intel.com,
        ricarkol@google.com, eric.auger@redhat.com, renzhengeek@gmail.com,
        reijiw@google.com, shan.gavin@gmail.com
Subject: [PATCH v4 3/4] KVM: arm64: Allow no running vcpu on restoring VGICv3 LPI pending status
Date:   Sat, 28 Jan 2023 07:51:49 +0800
Message-Id: <20230127235150.17025-4-gshan@redhat.com>
In-Reply-To: <20230127235150.17025-1-gshan@redhat.com>
References: <20230127235150.17025-1-gshan@redhat.com>
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Precedence: bulk

We don't have a running VCPU context to restore VGICv3 LPI pending status
due to command KVM_DEV_ARM_{VGIC_GRP_CTRL, ITS_RESTORE_TABLES} on KVM
device "kvm-arm-vgic-its".

Use vgic_write_guest_lock() to restore VGICv3 LPI pending status.

Signed-off-by: Gavin Shan <gshan@redhat.com>
Reviewed-by: Oliver Upton <oliver.upton@linux.dev>
---
 Documentation/virt/kvm/api.rst | 8 +++++---
 arch/arm64/kvm/vgic/vgic-v3.c  | 2 +-
 2 files changed, 6 insertions(+), 4 deletions(-)

diff --git a/Documentation/virt/kvm/api.rst b/Documentation/virt/kvm/api.rst
index 9807b05a1b57..5dc3598afbe2 100644
--- a/Documentation/virt/kvm/api.rst
+++ b/Documentation/virt/kvm/api.rst
@@ -8070,9 +8070,11 @@ considering the state as complete. VMM needs to ensure that the dirty
 state is final and avoid missing dirty pages from another ioctl ordered
 after the bitmap collection.
 
-NOTE: One example of using the backup bitmap is saving arm64 vgic/its
-tables through KVM_DEV_ARM_{VGIC_GRP_CTRL, ITS_SAVE_TABLES} command on
-KVM device "kvm-arm-vgic-its" when dirty ring is enabled.
+NOTE: Multiple examples of using the backup bitmap: (1) save vgic/its
+tables through command KVM_DEV_ARM_{VGIC_GRP_CTRL, ITS_SAVE_TABLES} on
+KVM device "kvm-arm-vgic-its". (2) restore vgic/its tables through
+command KVM_DEV_ARM_{VGIC_GRP_CTRL, ITS_RESTORE_TABLES} on KVM device
+"kvm-arm-vgic-its". VGICv3 LPI pending status is restored.
 
 8.30 KVM_CAP_XEN_HVM
 --------------------
diff --git a/arch/arm64/kvm/vgic/vgic-v3.c b/arch/arm64/kvm/vgic/vgic-v3.c
index 5dfbd03e5e1a..c94e4d7520fc 100644
--- a/arch/arm64/kvm/vgic/vgic-v3.c
+++ b/arch/arm64/kvm/vgic/vgic-v3.c
@@ -338,7 +338,7 @@ int vgic_v3_lpi_sync_pending_status(struct kvm *kvm, struct vgic_irq *irq)
 	if (status) {
 		/* clear consumed data */
 		val &= ~(1 << bit_nr);
-		ret = kvm_write_guest_lock(kvm, ptr, &val, 1);
+		ret = vgic_write_guest_lock(kvm, ptr, &val, 1);
 		if (ret)
 			return ret;
 	}
-- 
2.23.0