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[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] [xen staging] VT-d: generalize and correct "iommu=no-igfx" handling
commit 2d7f191b392e3efaf4f6e18e14b0b3c43a9e268b
Author: Jan Beulich <jbeulich@xxxxxxxx>
AuthorDate: Tue Oct 12 11:56:21 2021 +0200
Commit: Jan Beulich <jbeulich@xxxxxxxx>
CommitDate: Tue Oct 12 11:56:21 2021 +0200
VT-d: generalize and correct "iommu=no-igfx" handling
Linux'es supposedly equivalent "intel_iommu=igfx_off" deals with any
graphics devices (not just Intel ones) while at the same time limiting
the effect to IOMMUs covering only graphics devices. Keying the decision
to leave translation disabled for an IOMMU to merely a magic SBDF tuple
was wrong in the first place - systems may very well have non-graphics
devices at 0000:00:02.0 (ordinary root ports commonly live there, for
example). Any use of igd_drhd_address (and hence is_igd_drhd()) needs
further qualification.
Introduce a new "graphics only" field in struct acpi_drhd_unit and set
it according to device scope parsing outcome. Replace the bad use of
is_igd_drhd() in iommu_enable_translation() by use of this new field.
While adding the new field also convert the adjacent include_all one to
"bool".
Signed-off-by: Jan Beulich <jbeulich@xxxxxxxx>
Reviewed-by: Kevin Tian <kevin.tian@xxxxxxxxx>
Release-Acked-by: Ian Jackson <iwj@xxxxxxxxxxxxxx>
---
docs/misc/xen-command-line.pandoc | 4 ++--
xen/drivers/passthrough/vtd/dmar.c | 20 +++++++++++++++++++-
xen/drivers/passthrough/vtd/dmar.h | 3 ++-
xen/drivers/passthrough/vtd/iommu.c | 2 +-
4 files changed, 24 insertions(+), 5 deletions(-)
diff --git a/docs/misc/xen-command-line.pandoc
b/docs/misc/xen-command-line.pandoc
index b1f7978aa4..f7797ea233 100644
--- a/docs/misc/xen-command-line.pandoc
+++ b/docs/misc/xen-command-line.pandoc
@@ -1494,8 +1494,8 @@ The following options are specific to Intel VT-d hardware:
version 6 and greater as Registered-Based Invalidation isn't supported
by them.
-* The `igfx` boolean is active by default, and controls whether the IOMMU in
- front of an Intel Graphics Device is enabled or not.
+* The `igfx` boolean is active by default, and controls whether IOMMUs in
+ front of solely graphics devices get enabled or not.
It is intended as a debugging mechanism for graphics issues, and to be
similar to Linux's `intel_iommu=igfx_off` option. If specifying `no-igfx`
diff --git a/xen/drivers/passthrough/vtd/dmar.c
b/xen/drivers/passthrough/vtd/dmar.c
index 36d909b06d..d5ee367599 100644
--- a/xen/drivers/passthrough/vtd/dmar.c
+++ b/xen/drivers/passthrough/vtd/dmar.c
@@ -315,6 +315,7 @@ static int __init acpi_parse_dev_scope(
struct acpi_drhd_unit *drhd = type == DMAR_TYPE ?
container_of(scope, struct acpi_drhd_unit, scope) : NULL;
int depth, cnt, didx = 0, ret;
+ bool gfx_only = false;
if ( (cnt = scope_device_count(start, end)) < 0 )
return cnt;
@@ -324,6 +325,8 @@ static int __init acpi_parse_dev_scope(
scope->devices = xzalloc_array(u16, cnt);
if ( !scope->devices )
return -ENOMEM;
+
+ gfx_only = drhd && !drhd->include_all;
}
scope->devices_cnt = cnt;
@@ -354,6 +357,7 @@ static int __init acpi_parse_dev_scope(
acpi_scope->bus, sec_bus, sub_bus);
dmar_scope_add_buses(scope, sec_bus, sub_bus);
+ gfx_only = false;
break;
case ACPI_DMAR_SCOPE_TYPE_HPET:
@@ -374,6 +378,8 @@ static int __init acpi_parse_dev_scope(
acpi_hpet_unit->dev = path->dev;
acpi_hpet_unit->func = path->fn;
list_add(&acpi_hpet_unit->list, &drhd->hpet_list);
+
+ gfx_only = false;
}
break;
@@ -388,6 +394,12 @@ static int __init acpi_parse_dev_scope(
if ( (seg == 0) && (bus == 0) && (path->dev == 2) &&
(path->fn == 0) )
igd_drhd_address = drhd->address;
+
+ if ( gfx_only &&
+ pci_conf_read8(PCI_SBDF(seg, bus, path->dev, path->fn),
+ PCI_CLASS_DEVICE + 1) != 0x03
+ /* PCI_BASE_CLASS_DISPLAY */ )
+ gfx_only = false;
}
break;
@@ -408,6 +420,8 @@ static int __init acpi_parse_dev_scope(
acpi_ioapic_unit->ioapic.bdf.dev = path->dev;
acpi_ioapic_unit->ioapic.bdf.func = path->fn;
list_add(&acpi_ioapic_unit->list, &drhd->ioapic_list);
+
+ gfx_only = false;
}
break;
@@ -417,11 +431,15 @@ static int __init acpi_parse_dev_scope(
printk(XENLOG_WARNING VTDPREFIX "Unknown scope type %#x\n",
acpi_scope->entry_type);
start += acpi_scope->length;
+ gfx_only = false;
continue;
}
scope->devices[didx++] = PCI_BDF(bus, path->dev, path->fn);
start += acpi_scope->length;
- }
+ }
+
+ if ( drhd && gfx_only )
+ drhd->gfx_only = true;
ret = 0;
diff --git a/xen/drivers/passthrough/vtd/dmar.h
b/xen/drivers/passthrough/vtd/dmar.h
index a44820a5e7..a1f2353a51 100644
--- a/xen/drivers/passthrough/vtd/dmar.h
+++ b/xen/drivers/passthrough/vtd/dmar.h
@@ -62,7 +62,8 @@ struct acpi_drhd_unit {
struct list_head list;
u64 address; /* register base address of the unit */
u16 segment;
- u8 include_all:1;
+ bool include_all:1;
+ bool gfx_only:1;
struct vtd_iommu *iommu;
struct list_head ioapic_list;
struct list_head hpet_list;
diff --git a/xen/drivers/passthrough/vtd/iommu.c
b/xen/drivers/passthrough/vtd/iommu.c
index 0519dfc9e7..137aea2c92 100644
--- a/xen/drivers/passthrough/vtd/iommu.c
+++ b/xen/drivers/passthrough/vtd/iommu.c
@@ -751,7 +751,7 @@ static void iommu_enable_translation(struct acpi_drhd_unit
*drhd)
unsigned long flags;
struct vtd_iommu *iommu = drhd->iommu;
- if ( is_igd_drhd(drhd) )
+ if ( drhd->gfx_only )
{
if ( !iommu_igfx )
{
--
generated by git-patchbot for /home/xen/git/xen.git#staging
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