@@ -663,34 +663,34 @@ static int msi_capability_init(struct pci_dev *dev,
return 0;
}
-static u64 read_pci_mem_bar(u16 seg, u8 bus, u8 slot, u8 func, u8 bir, int vf)
+static uint64_t read_pci_mem_bar(pci_sbdf_t sbdf, uint8_t bir, int vf,
+ const struct pf_info *pf_info)
{
+ uint16_t seg = sbdf.seg;
+ uint8_t bus = sbdf.bus, slot = sbdf.dev, func = sbdf.fn;
u8 limit;
u32 addr, base = PCI_BASE_ADDRESS_0;
u64 disp = 0;
if ( vf >= 0 )
{
- struct pci_dev *pdev = pci_get_pdev(NULL,
- PCI_SBDF(seg, bus, slot, func));
unsigned int pos;
uint16_t ctrl, num_vf, offset, stride;
- if ( !pdev )
- return 0;
+ ASSERT(pf_info);
- pos = pci_find_ext_capability(pdev->sbdf, PCI_EXT_CAP_ID_SRIOV);
- ctrl = pci_conf_read16(pdev->sbdf, pos + PCI_SRIOV_CTRL);
- num_vf = pci_conf_read16(pdev->sbdf, pos + PCI_SRIOV_NUM_VF);
- offset = pci_conf_read16(pdev->sbdf, pos + PCI_SRIOV_VF_OFFSET);
- stride = pci_conf_read16(pdev->sbdf, pos + PCI_SRIOV_VF_STRIDE);
+ pos = pci_find_ext_capability(sbdf, PCI_EXT_CAP_ID_SRIOV);
+ ctrl = pci_conf_read16(sbdf, pos + PCI_SRIOV_CTRL);
+ num_vf = pci_conf_read16(sbdf, pos + PCI_SRIOV_NUM_VF);
+ offset = pci_conf_read16(sbdf, pos + PCI_SRIOV_VF_OFFSET);
+ stride = pci_conf_read16(sbdf, pos + PCI_SRIOV_VF_STRIDE);
if ( !pos ||
!(ctrl & PCI_SRIOV_CTRL_VFE) ||
!(ctrl & PCI_SRIOV_CTRL_MSE) ||
!num_vf || !offset || (num_vf > 1 && !stride) ||
bir >= PCI_SRIOV_NUM_BARS ||
- !pdev->vf_rlen[bir] )
+ !pf_info->vf_rlen[bir] )
return 0;
base = pos + PCI_SRIOV_BAR;
vf -= PCI_BDF(bus, slot, func) + offset;
@@ -704,8 +704,8 @@ static u64 read_pci_mem_bar(u16 seg, u8 bus, u8 slot, u8 func, u8 bir, int vf)
}
if ( vf >= num_vf )
return 0;
- BUILD_BUG_ON(ARRAY_SIZE(pdev->vf_rlen) != PCI_SRIOV_NUM_BARS);
- disp = vf * pdev->vf_rlen[bir];
+ BUILD_BUG_ON(ARRAY_SIZE(pf_info->vf_rlen) != PCI_SRIOV_NUM_BARS);
+ disp = vf * pf_info->vf_rlen[bir];
limit = PCI_SRIOV_NUM_BARS;
}
else switch ( pci_conf_read8(PCI_SBDF(seg, bus, slot, func),
@@ -814,6 +814,7 @@ static int msix_capability_init(struct pci_dev *dev,
int vf;
paddr_t pba_paddr;
unsigned int pba_offset;
+ const struct pf_info *pf_info;
if ( !dev->info.is_virtfn )
{
@@ -821,6 +822,7 @@ static int msix_capability_init(struct pci_dev *dev,
pslot = slot;
pfunc = func;
vf = -1;
+ pf_info = NULL;
}
else
{
@@ -828,9 +830,12 @@ static int msix_capability_init(struct pci_dev *dev,
pslot = PCI_SLOT(dev->info.physfn.devfn);
pfunc = PCI_FUNC(dev->info.physfn.devfn);
vf = dev->sbdf.bdf;
+ ASSERT(dev->pf_pdev);
+ pf_info = &dev->pf_pdev->physfn;
}
- table_paddr = read_pci_mem_bar(seg, pbus, pslot, pfunc, bir, vf);
+ table_paddr = read_pci_mem_bar(PCI_SBDF(seg, pbus, pslot, pfunc), bir,
+ vf, pf_info);
WARN_ON(msi && msi->table_base != table_paddr);
if ( !table_paddr )
{
@@ -853,7 +858,8 @@ static int msix_capability_init(struct pci_dev *dev,
pba_offset = pci_conf_read32(dev->sbdf, msix_pba_offset_reg(pos));
bir = (u8)(pba_offset & PCI_MSIX_BIRMASK);
- pba_paddr = read_pci_mem_bar(seg, pbus, pslot, pfunc, bir, vf);
+ pba_paddr = read_pci_mem_bar(PCI_SBDF(seg, pbus, pslot, pfunc), bir, vf,
+ pf_info);
WARN_ON(!pba_paddr);
pba_paddr += pba_offset & ~PCI_MSIX_BIRMASK;
@@ -735,7 +735,7 @@ int pci_add_device(u16 seg, u8 bus, u8 devfn,
}
}
- if ( !pdev->info.is_virtfn && !pdev->vf_rlen[0] )
+ if ( !pdev->info.is_virtfn && !pdev->physfn.vf_rlen[0] )
{
unsigned int pos = pci_find_ext_capability(pdev->sbdf,
PCI_EXT_CAP_ID_SRIOV);
@@ -747,7 +747,9 @@ int pci_add_device(u16 seg, u8 bus, u8 devfn,
{
unsigned int i;
- BUILD_BUG_ON(ARRAY_SIZE(pdev->vf_rlen) != PCI_SRIOV_NUM_BARS);
+ BUILD_BUG_ON(ARRAY_SIZE(pdev->physfn.vf_rlen) !=
+ PCI_SRIOV_NUM_BARS);
+
for ( i = 0; i < PCI_SRIOV_NUM_BARS; )
{
unsigned int idx = pos + PCI_SRIOV_BAR + i * 4;
@@ -762,7 +764,7 @@ int pci_add_device(u16 seg, u8 bus, u8 devfn,
continue;
}
ret = pci_size_mem_bar(pdev->sbdf, idx, NULL,
- &pdev->vf_rlen[i],
+ &pdev->physfn.vf_rlen[i],
PCI_BAR_VF |
((i == PCI_SRIOV_NUM_BARS - 1) ?
PCI_BAR_LAST : 0));
@@ -159,9 +159,14 @@ struct pci_dev {
* List entry if VF.
*/
struct list_head vf_list;
- u64 vf_rlen[6];
- /* Link from VF to PF. Only populated for VFs. */
- const struct pci_dev *pf_pdev;
+ union {
+ struct pf_info {
+ /* Only populated for PFs. */
+ uint64_t vf_rlen[PCI_SRIOV_NUM_BARS];
+ } physfn;
+ /* Link from VF to PF. Only populated for VFs. */
+ const struct pci_dev *pf_pdev;
+ };
/* Data for vPCI. */
struct vpci *vpci;
In commit 4f78438b45e2 ("vpci: use per-domain PCI lock to protect vpci structure") a lock was moved from allocate_and_map_msi_pirq() to the caller and changed from pcidevs_lock() to read_lock(&d->pci_lock). However, one call path wasn't updated to reflect the change, leading to a failed assertion observed under the following conditions: * PV dom0 * Debug build (CONFIG_DEBUG=y) of Xen * There is an SR-IOV device in the system with one or more VFs enabled * Dom0 has loaded the driver for the VF and enabled MSI-X (XEN) Assertion 'd || pcidevs_locked()' failed at drivers/passthrough/pci.c:535 (XEN) ----[ Xen-4.20-unstable x86_64 debug=y Not tainted ]---- ... (XEN) Xen call trace: (XEN) [<ffff82d040284da8>] R pci_get_pdev+0x4c/0xab (XEN) [<ffff82d040344f5c>] F arch/x86/msi.c#read_pci_mem_bar+0x58/0x272 (XEN) [<ffff82d04034530e>] F arch/x86/msi.c#msix_capability_init+0x198/0x755 (XEN) [<ffff82d040345dad>] F arch/x86/msi.c#__pci_enable_msix+0x82/0xe8 (XEN) [<ffff82d0403463e5>] F pci_enable_msi+0x3f/0x78 (XEN) [<ffff82d04034be2b>] F map_domain_pirq+0x2a4/0x6dc (XEN) [<ffff82d04034d4d5>] F allocate_and_map_msi_pirq+0x103/0x262 (XEN) [<ffff82d04035da5d>] F physdev_map_pirq+0x210/0x259 (XEN) [<ffff82d04035e798>] F do_physdev_op+0x9c3/0x1454 (XEN) [<ffff82d040329475>] F pv_hypercall+0x5ac/0x6af (XEN) [<ffff82d0402012d3>] F lstar_enter+0x143/0x150 In read_pci_mem_bar(), the VF obtains the struct pci_dev pointer for its associated PF to access the vf_rlen array. This array is initialized in pci_add_device() and is only populated in the associated PF's struct pci_dev. Access the vf_rlen array via the link to the PF, and remove the troublesome call to pci_get_pdev(). Fixes: 4f78438b45e2 ("vpci: use per-domain PCI lock to protect vpci structure") Reported-by: Teddy Astie <teddy.astie@vates.tech> Signed-off-by: Stewart Hildebrand <stewart.hildebrand@amd.com> Reviewed-by: Jan Beulich <jbeulich@suse.com> --- Candidate for backport to 4.19 Patch #1 ("xen/pci: introduce PF<->VF links") is pre-requisite v7->v8: * no change v6->v7: * turn NULL-check into ASSERT * adjust commentary in struct pf_info v5->v6: * add Jan's R-b v4->v5: * split the PF<->VF links to a pre-requisite patch * pass pci_sbdf_t to read_pci_mem_bar() * use stdint.h types on changed lines * re-add NULL check for pf_info in read_pci_mem_bar(), as pf_info could be NULL v3->v4: * handle case when PF is removed with VFs enabled, then re-added with VFs disabled v2->v3: * link from VF to PF's struct pci_dev * v1->v2: * remove call to pci_get_pdev() --- xen/arch/x86/msi.c | 36 ++++++++++++++++++++--------------- xen/drivers/passthrough/pci.c | 8 +++++--- xen/include/xen/pci.h | 11 ++++++++--- 3 files changed, 34 insertions(+), 21 deletions(-)