Mailing List Archive

commit 418b4d57416428c5bb5a3e796214367cbdcd9423
Author: Jan Beulich <jbeulich@suse.com>
AuthorDate: Thu Sep 16 11:02:08 2021 +0200
Commit: Jan Beulich <jbeulich@suse.com>
CommitDate: Thu Sep 16 11:02:08 2021 +0200

VT-d: defer "no DRHD" check when (un)mapping devices

If devices are to be skipped anyway (which is the case in particular for
host bridges), there's no point complaining about a missing DRHD (and
hence a missing association with an IOMMU).

While there convert assignments to initializers and constify "drhd"
local variables.

Signed-off-by: Jan Beulich <jbeulich@suse.com>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
---
xen/drivers/passthrough/vtd/iommu.c | 29 ++++++++++++++++-------------
1 file changed, 16 insertions(+), 13 deletions(-)

diff --git a/xen/drivers/passthrough/vtd/iommu.c b/xen/drivers/passthrough/vtd/iommu.c
index bab19d79e8..9827ab184d 100644
--- a/xen/drivers/passthrough/vtd/iommu.c
+++ b/xen/drivers/passthrough/vtd/iommu.c
@@ -1460,14 +1460,10 @@ static int domain_context_unmap(struct domain *d, uint8_t devfn,
static int domain_context_mapping(struct domain *domain, u8 devfn,
struct pci_dev *pdev)
{
- struct acpi_drhd_unit *drhd;
+ const struct acpi_drhd_unit *drhd = acpi_find_matched_drhd_unit(pdev);
int ret = 0;
u8 seg = pdev->seg, bus = pdev->bus, secbus;

- drhd = acpi_find_matched_drhd_unit(pdev);
- if ( !drhd )
- return -ENODEV;
-
/*
* Generally we assume only devices from one node to get assigned to a
* given guest. But even if not, by replacing the prior value here we
@@ -1476,7 +1472,7 @@ static int domain_context_mapping(struct domain *domain, u8 devfn,
* this or other devices may be penalized then, but some would also be
* if we left other than NUMA_NO_NODE untouched here.
*/
- if ( drhd->iommu->node != NUMA_NO_NODE )
+ if ( drhd && drhd->iommu->node != NUMA_NO_NODE )
dom_iommu(domain)->node = drhd->iommu->node;

ASSERT(pcidevs_locked());
@@ -1497,6 +1493,9 @@ static int domain_context_mapping(struct domain *domain, u8 devfn,
break;

case DEV_TYPE_PCIe_ENDPOINT:
+ if ( !drhd )
+ return -ENODEV;
+
if ( iommu_debug )
printk(VTDPREFIX "%pd:PCIe: map %pp\n",
domain, &PCI_SBDF3(seg, bus, devfn));
@@ -1508,6 +1507,9 @@ static int domain_context_mapping(struct domain *domain, u8 devfn,
break;

case DEV_TYPE_PCI:
+ if ( !drhd )
+ return -ENODEV;
+
if ( iommu_debug )
printk(VTDPREFIX "%pd:PCI: map %pp\n",
domain, &PCI_SBDF3(seg, bus, devfn));
@@ -1651,17 +1653,12 @@ int domain_context_unmap_one(
static int domain_context_unmap(struct domain *domain, u8 devfn,
struct pci_dev *pdev)
{
- struct acpi_drhd_unit *drhd;
- struct vtd_iommu *iommu;
+ const struct acpi_drhd_unit *drhd = acpi_find_matched_drhd_unit(pdev);
+ struct vtd_iommu *iommu = drhd ? drhd->iommu : NULL;
int ret;
u8 seg = pdev->seg, bus = pdev->bus, tmp_bus, tmp_devfn, secbus;
int found = 0;

- drhd = acpi_find_matched_drhd_unit(pdev);
- if ( !drhd )
- return -ENODEV;
- iommu = drhd->iommu;
-
switch ( pdev->type )
{
case DEV_TYPE_PCI_HOST_BRIDGE:
@@ -1676,6 +1673,9 @@ static int domain_context_unmap(struct domain *domain, u8 devfn,
return 0;

case DEV_TYPE_PCIe_ENDPOINT:
+ if ( !iommu )
+ return -ENODEV;
+
if ( iommu_debug )
printk(VTDPREFIX "%pd:PCIe: unmap %pp\n",
domain, &PCI_SBDF3(seg, bus, devfn));
@@ -1686,6 +1686,9 @@ static int domain_context_unmap(struct domain *domain, u8 devfn,
break;

case DEV_TYPE_PCI:
+ if ( !iommu )
+ return -ENODEV;
+
if ( iommu_debug )
printk(VTDPREFIX "%pd:PCI: unmap %pp\n",
domain, &PCI_SBDF3(seg, bus, devfn));
--
generated by git-patchbot for /home/xen/git/xen.git#staging