qemu/virtio-pci-compat-page-aligned-ATS.patch

From: Jason Wang <jasowang@redhat.com>
Date: Tue, 6 Apr 2021 12:03:30 +0800
Subject: virtio-pci: compat page aligned ATS

Git-commit: d83f46d189a26fa32434139954d264326f199a45

Commit 4c70875372b8 ("pci: advertise a page aligned ATS") advertises
the page aligned via ATS capability (RO) to unbrek recent Linux IOMMU
drivers since 5.2. But it forgot the compat the capability which
breaks the migration from old machine type:

(qemu) qemu-kvm: get_pci_config_device: Bad config data: i=0x104 read:
0 device: 20 cmask: ff wmask: 0 w1cmask:0

This patch introduces a new parameter "x-ats-page-aligned" for
virtio-pci device and turns it on for machine type which is newer than
5.1.

Cc: Michael S. Tsirkin <mst@redhat.com>
Cc: Peter Xu <peterx@redhat.com>
Cc: Dr. David Alan Gilbert <dgilbert@redhat.com>
Cc: qemu-stable@nongnu.org
Fixes: 4c70875372b8 ("pci: advertise a page aligned ATS")
Signed-off-by: Jason Wang <jasowang@redhat.com>
Message-Id: <20210406040330.11306-1-jasowang@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Bruce Rogers <brogers@suse.com>
---
 hw/core/machine.c      |  1 +
 hw/pci/pcie.c          | 10 ++++++----
 hw/virtio/virtio-pci.c |  5 ++++-
 hw/virtio/virtio-pci.h |  5 +++++
 include/hw/pci/pcie.h  |  2 +-
 5 files changed, 17 insertions(+), 6 deletions(-)

diff --git a/hw/core/machine.c b/hw/core/machine.c
index 72ceba57def38ca9dd5c683a71c4..7e99d0a05bdf1a7c898bc8923a77 100644
--- a/hw/core/machine.c
+++ b/hw/core/machine.c
@@ -37,6 +37,7 @@ GlobalProperty hw_compat_5_1[] = {
     { "nvme", "use-intel-id", "on"},
     { "pvpanic", "events", "1"}, /* PVPANIC_PANICKED */
     { "pl011", "migrate-clk", "off" },
+    { "virtio-pci", "x-ats-page-aligned", "off"},
 };
 const size_t hw_compat_5_1_len = G_N_ELEMENTS(hw_compat_5_1);
 
diff --git a/hw/pci/pcie.c b/hw/pci/pcie.c
index d4010cf8f36178758315627d56bb..8bbabd6e2bb7b03c0f786e977fbf 100644
--- a/hw/pci/pcie.c
+++ b/hw/pci/pcie.c
@@ -964,16 +964,18 @@ void pcie_dev_ser_num_init(PCIDevice *dev, uint16_t offset, uint64_t ser_num)
     pci_set_quad(dev->config + offset + pci_dsn_cap, ser_num);
 }
 
-void pcie_ats_init(PCIDevice *dev, uint16_t offset)
+void pcie_ats_init(PCIDevice *dev, uint16_t offset, bool aligned)
 {
     pcie_add_capability(dev, PCI_EXT_CAP_ID_ATS, 0x1,
                         offset, PCI_EXT_CAP_ATS_SIZEOF);
 
     dev->exp.ats_cap = offset;
 
-    /* Invalidate Queue Depth 0, Page Aligned Request 1 */
-    pci_set_word(dev->config + offset + PCI_ATS_CAP,
-                 PCI_ATS_CAP_PAGE_ALIGNED);
+    /* Invalidate Queue Depth 0 */
+    if (aligned) {
+        pci_set_word(dev->config + offset + PCI_ATS_CAP,
+                     PCI_ATS_CAP_PAGE_ALIGNED);
+    }
     /* STU 0, Disabled by default */
     pci_set_word(dev->config + offset + PCI_ATS_CTRL, 0);
 
diff --git a/hw/virtio/virtio-pci.c b/hw/virtio/virtio-pci.c
index f863f69ede4f4bf1c09fc39a5035..b7ab325ae99176ae18ee64a0bfa5 100644
--- a/hw/virtio/virtio-pci.c
+++ b/hw/virtio/virtio-pci.c
@@ -1840,7 +1840,8 @@ static void virtio_pci_realize(PCIDevice *pci_dev, Error **errp)
         }
 
         if (proxy->flags & VIRTIO_PCI_FLAG_ATS) {
-            pcie_ats_init(pci_dev, last_pcie_cap_offset);
+            pcie_ats_init(pci_dev, last_pcie_cap_offset,
+                          proxy->flags & VIRTIO_PCI_FLAG_ATS_PAGE_ALIGNED);
             last_pcie_cap_offset += PCI_EXT_CAP_ATS_SIZEOF;
         }
 
@@ -1917,6 +1918,8 @@ static Property virtio_pci_properties[] = {
                      ignore_backend_features, false),
     DEFINE_PROP_BIT("ats", VirtIOPCIProxy, flags,
                     VIRTIO_PCI_FLAG_ATS_BIT, false),
+    DEFINE_PROP_BIT("x-ats-page-aligned", VirtIOPCIProxy, flags,
+                    VIRTIO_PCI_FLAG_ATS_PAGE_ALIGNED_BIT, true),
     DEFINE_PROP_BIT("x-pcie-deverr-init", VirtIOPCIProxy, flags,
                     VIRTIO_PCI_FLAG_INIT_DEVERR_BIT, true),
     DEFINE_PROP_BIT("x-pcie-lnkctl-init", VirtIOPCIProxy, flags,
diff --git a/hw/virtio/virtio-pci.h b/hw/virtio/virtio-pci.h
index d7d5d403a9483f5f7e0f0f9b4110..2446dcd9aef197964b59f83b6183 100644
--- a/hw/virtio/virtio-pci.h
+++ b/hw/virtio/virtio-pci.h
@@ -42,6 +42,7 @@ enum {
     VIRTIO_PCI_FLAG_INIT_PM_BIT,
     VIRTIO_PCI_FLAG_INIT_FLR_BIT,
     VIRTIO_PCI_FLAG_AER_BIT,
+    VIRTIO_PCI_FLAG_ATS_PAGE_ALIGNED_BIT,
 };
 
 /* Need to activate work-arounds for buggy guests at vmstate load. */
@@ -84,6 +85,10 @@ enum {
 /* Advanced Error Reporting capability */
 #define VIRTIO_PCI_FLAG_AER (1 << VIRTIO_PCI_FLAG_AER_BIT)
 
+/* Page Aligned Address space Translation Service */
+#define VIRTIO_PCI_FLAG_ATS_PAGE_ALIGNED \
+  (1 << VIRTIO_PCI_FLAG_ATS_PAGE_ALIGNED_BIT)
+
 typedef struct {
     MSIMessage msg;
     int virq;
diff --git a/include/hw/pci/pcie.h b/include/hw/pci/pcie.h
index 14c58ebdb6ec1fd5dc3c8563fed9..6063bee0ec632c563f236f520aef 100644
--- a/include/hw/pci/pcie.h
+++ b/include/hw/pci/pcie.h
@@ -137,7 +137,7 @@ void pcie_acs_reset(PCIDevice *dev);
 
 void pcie_ari_init(PCIDevice *dev, uint16_t offset, uint16_t nextfn);
 void pcie_dev_ser_num_init(PCIDevice *dev, uint16_t offset, uint64_t ser_num);
-void pcie_ats_init(PCIDevice *dev, uint16_t offset);
+void pcie_ats_init(PCIDevice *dev, uint16_t offset, bool aligned);
 
 void pcie_cap_slot_pre_plug_cb(HotplugHandler *hotplug_dev, DeviceState *dev,
                                Error **errp);