[PATCH v8 04/15] pcie_sriov: Do not reset NumVFs after disabling VFs

From: Akihiko Odaki <akihiko.odaki@daynix.com>
To: "Philippe Mathieu-Daudé" <philmd@linaro.org>,
	"Michael S. Tsirkin" <mst@redhat.com>,
	"Marcel Apfelbaum" <marcel.apfelbaum@gmail.com>,
	"Alex Williamson" <alex.williamson@redhat.com>,
	"Cédric Le Goater" <clg@redhat.com>,
	"Paolo Bonzini" <pbonzini@redhat.com>,
	"Daniel P. Berrangé" <berrange@redhat.com>,
	"Eduardo Habkost" <eduardo@habkost.net>,
	"Sriram Yagnaraman" <sriram.yagnaraman@ericsson.com>,
	"Jason Wang" <jasowang@redhat.com>,
	"Keith Busch" <kbusch@kernel.org>,
	"Klaus Jensen" <its@irrelevant.dk>,
	"Markus Armbruster" <armbru@redhat.com>
Cc: qemu-devel@nongnu.org, qemu-block@nongnu.org,
	 Akihiko Odaki <akihiko.odaki@daynix.com>
Subject: [PATCH v8 04/15] pcie_sriov: Do not reset NumVFs after disabling VFs
Date: Wed, 28 Feb 2024 20:33:15 +0900	[thread overview]
Message-ID: <20240228-reuse-v8-4-282660281e60@daynix.com> (raw)
In-Reply-To: <20240228-reuse-v8-0-282660281e60@daynix.com>

The spec does not NumVFs is reset after disabling VFs except when
resetting the PF. Clearing it is guest visible and out of spec, even
though Linux doesn't rely on this value being preserved, so we never
noticed.

Fixes: 7c0fa8dff811 ("pcie: Add support for Single Root I/O Virtualization (SR/IOV)")
Signed-off-by: Akihiko Odaki <akihiko.odaki@daynix.com>
---
 hw/pci/pcie_sriov.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/hw/pci/pcie_sriov.c b/hw/pci/pcie_sriov.c
index 51b66d1bb342..e9b23221d713 100644
--- a/hw/pci/pcie_sriov.c
+++ b/hw/pci/pcie_sriov.c
@@ -215,7 +215,6 @@ static void unregister_vfs(PCIDevice *dev)
     g_free(dev->exp.sriov_pf.vf);
     dev->exp.sriov_pf.vf = NULL;
     dev->exp.sriov_pf.num_vfs = 0;
-    pci_set_word(dev->config + dev->exp.sriov_cap + PCI_SRIOV_NUM_VF, 0);
 }
 
 void pcie_sriov_config_write(PCIDevice *dev, uint32_t address,
@@ -260,6 +259,8 @@ void pcie_sriov_pf_reset(PCIDevice *dev)
     pci_set_word(dev->config + sriov_cap + PCI_SRIOV_CTRL, 0);
     unregister_vfs(dev);
 
+    pci_set_word(dev->config + sriov_cap + PCI_SRIOV_NUM_VF, 0);
+
     /*
      * Default is to use 4K pages, software can modify it
      * to any of the supported bits

-- 
2.43.2


