[v3] virtio: features,fixes

[PULL v3 12/85] virtio-pci: only reset pm state during resetting

Michael S. Tsirkin posted 85 patches 2 months, 2 weeks ago

Diff against v1 v1 v2 v2 v3
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Maintainers: David Hildenbrand <david@redhat.com>, Igor Mammedov <imammedo@redhat.com>, Raphael Norwitz <raphael@enfabrica.net>, "Michael S. Tsirkin" <mst@redhat.com>, Gerd Hoffmann <kraxel@redhat.com>, Marcel Apfelbaum <marcel.apfelbaum@gmail.com>, Shannon Zhao <shannon.zhaosl@gmail.com>, Ani Sinha <anisinha@redhat.com>, Peter Maydell <peter.maydell@linaro.org>, Kevin Wolf <kwolf@redhat.com>, Hanna Reitz <hreitz@redhat.com>, Eduardo Habkost <eduardo@habkost.net>, "Philippe Mathieu-Daudé" <philmd@linaro.org>, Yanan Wang <wangyanan55@huawei.com>, Jonathan Cameron <jonathan.cameron@huawei.com>, Fan Ni <fan.ni@samsung.com>, "Marc-André Lureau" <marcandre.lureau@redhat.com>, Paolo Bonzini <pbonzini@redhat.com>, Richard Henderson <richard.henderson@linaro.org>, Sergio Lopez <slp@redhat.com>, Akihiko Odaki <akihiko.odaki@daynix.com>, Sriram Yagnaraman <sriram.yagnaraman@ericsson.com>, Jason Wang <jasowang@redhat.com>, Keith Busch <kbusch@kernel.org>, Klaus Jensen <its@irrelevant.dk>, Jesper Devantier <foss@defmacro.it>, Nicholas Piggin <npiggin@gmail.com>, Daniel Henrique Barboza <danielhb413@gmail.com>, David Gibson <david@gibson.dropbear.id.au>, Harsh Prateek Bora <harshpb@linux.ibm.com>, Halil Pasic <pasic@linux.ibm.com>, Christian Borntraeger <borntraeger@linux.ibm.com>, Eric Farman <farman@linux.ibm.com>, Ilya Leoshkevich <iii@linux.ibm.com>, Thomas Huth <thuth@redhat.com>, Fam Zheng <fam@euphon.net>, "Alex Bennée" <alex.bennee@linaro.org>, Stefan Hajnoczi <stefanha@redhat.com>, Eric Auger <eric.auger@redhat.com>, Stefano Stabellini <sstabellini@kernel.org>, Anthony PERARD <anthony@xenproject.org>, Paul Durrant <paul@xen.org>, Cornelia Huck <cohuck@redhat.com>, "Daniel P. Berrangé" <berrange@redhat.com>, Eric Blake <eblake@redhat.com>, Markus Armbruster <armbru@redhat.com>, Marcelo Tosatti <mtosatti@redhat.com>, David Woodhouse <dwmw2@infradead.org>, Laurent Vivier <lvivier@redhat.com>, Coiby Xu <Coiby.Xu@gmail.com>

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[PULL v3 12/85] virtio-pci: only reset pm state during resetting

Posted by Michael S. Tsirkin 2 months, 2 weeks ago

From: Jiqian Chen <Jiqian.Chen@amd.com>

Fix bug imported by 27ce0f3afc9dd ("fix Power Management Control Register for PCI Express virtio devices"
After this change, observe that QEMU may erroneously clear the power status of the device,
or may erroneously clear non writable registers, such as NO_SOFT_RESET, etc.

Only state of PM_CTRL is writable.
Only when flag VIRTIO_PCI_FLAG_INIT_PM is set, need to reset state.

Fixes: 27ce0f3afc9dd ("fix Power Management Control Register for PCI Express virtio devices"
Signed-off-by: Jiqian Chen <Jiqian.Chen@amd.com>
Message-Id: <20240515073526.17297-2-Jiqian.Chen@amd.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
---
 hw/virtio/virtio-pci.c | 8 +++++++-
 1 file changed, 7 insertions(+), 1 deletion(-)

diff --git a/hw/virtio/virtio-pci.c b/hw/virtio/virtio-pci.c
index cffc7efcae..7d62e92365 100644
--- a/hw/virtio/virtio-pci.c
+++ b/hw/virtio/virtio-pci.c
@@ -2306,10 +2306,16 @@ static void virtio_pci_bus_reset_hold(Object *obj, ResetType type)
     virtio_pci_reset(qdev);
 
     if (pci_is_express(dev)) {
+        VirtIOPCIProxy *proxy = VIRTIO_PCI(dev);
+
         pcie_cap_deverr_reset(dev);
         pcie_cap_lnkctl_reset(dev);
 
-        pci_set_word(dev->config + dev->exp.pm_cap + PCI_PM_CTRL, 0);
+        if (proxy->flags & VIRTIO_PCI_FLAG_INIT_PM) {
+            pci_word_test_and_clear_mask(
+                dev->config + dev->exp.pm_cap + PCI_PM_CTRL,
+                PCI_PM_CTRL_STATE_MASK);
+        }
     }
 }
 
-- 
MST