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[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] [PATCH v2 1/2] x86/iommu: account for IOMEM caps when populating dom0 IOMMU page-tables
The current code in arch_iommu_hwdom_init() kind of open-codes the same
MMIO permission ranges that are added to the hardware domain ->iomem_caps.
Avoid this duplication and use ->iomem_caps in arch_iommu_hwdom_init() to
filter which memory regions should be added to the dom0 IOMMU page-tables.
This should result in no change in the memory regions that end up identity
mapped in the domain IOMMU page tables.
Note the IO-APIC and MCFG page(s) must be set as not accessible for a PVH
dom0, otherwise the internal Xen emulation for those ranges won't work.
This requires an adjustment in dom0_setup_permissions().
Also the special casing of E820_UNUSABLE regions no longer needs to be done
in arch_iommu_hwdom_init(), as those regions are already blocked in
->iomem_caps and thus would be removed from the rangeset as part of
->iomem_caps processing in arch_iommu_hwdom_init().
Suggested-by: Jan Beulich <jbeulich@xxxxxxxx>
Signed-off-by: Roger Pau Monné <roger.pau@xxxxxxxxxx>
---
Changes since v1:
- New in this version.
---
xen/arch/x86/dom0_build.c | 19 ++++++++-
xen/arch/x86/hvm/io.c | 16 --------
xen/arch/x86/include/asm/hvm/io.h | 3 --
xen/drivers/passthrough/x86/iommu.c | 61 +++++++++++++----------------
4 files changed, 45 insertions(+), 54 deletions(-)
diff --git a/xen/arch/x86/dom0_build.c b/xen/arch/x86/dom0_build.c
index e8f5bf5447bc..22da9ba5a362 100644
--- a/xen/arch/x86/dom0_build.c
+++ b/xen/arch/x86/dom0_build.c
@@ -552,7 +552,8 @@ int __init dom0_setup_permissions(struct domain *d)
for ( i = 0; i < nr_ioapics; i++ )
{
mfn = paddr_to_pfn(mp_ioapics[i].mpc_apicaddr);
- if ( !rangeset_contains_singleton(mmio_ro_ranges, mfn) )
+ if ( is_hvm_domain(d) ||
+ !rangeset_contains_singleton(mmio_ro_ranges, mfn) )
rc |= iomem_deny_access(d, mfn, mfn);
}
/* MSI range. */
@@ -593,6 +594,22 @@ int __init dom0_setup_permissions(struct domain *d)
rc |= rangeset_add_singleton(mmio_ro_ranges, mfn);
}
+ /* For PVH dom0 prevent access to MCFG, it's emulated by Xen. */
+ if ( is_hvm_domain(d) )
+ {
+ for ( i = 0; i < pci_mmcfg_config_num; i++ )
+ {
+ const unsigned long s =
+ PFN_DOWN(pci_mmcfg_config[i].address) +
+ PCI_BDF(pci_mmcfg_config[i].start_bus_number, 0, 0);
+ const unsigned long e =
+ PFN_DOWN(pci_mmcfg_config[i].address) +
+ PCI_BDF(pci_mmcfg_config[i].end_bus_number, ~0, ~0);
+
+ rc |= iomem_deny_access(d, s, e);
+ }
+ }
+
return rc;
}
diff --git a/xen/arch/x86/hvm/io.c b/xen/arch/x86/hvm/io.c
index db726b38177b..174c3285a636 100644
--- a/xen/arch/x86/hvm/io.c
+++ b/xen/arch/x86/hvm/io.c
@@ -363,22 +363,6 @@ static const struct hvm_mmcfg *vpci_mmcfg_find(const
struct domain *d,
return NULL;
}
-int __hwdom_init vpci_subtract_mmcfg(const struct domain *d, struct rangeset
*r)
-{
- const struct hvm_mmcfg *mmcfg;
-
- list_for_each_entry ( mmcfg, &d->arch.hvm.mmcfg_regions, next )
- {
- int rc = rangeset_remove_range(r, PFN_DOWN(mmcfg->addr),
- PFN_DOWN(mmcfg->addr + mmcfg->size -
1));
-
- if ( rc )
- return rc;
- }
-
- return 0;
-}
-
static unsigned int vpci_mmcfg_decode_addr(const struct hvm_mmcfg *mmcfg,
paddr_t addr, pci_sbdf_t *sbdf)
{
diff --git a/xen/arch/x86/include/asm/hvm/io.h
b/xen/arch/x86/include/asm/hvm/io.h
index f2b8431facb0..0881e9e9f72d 100644
--- a/xen/arch/x86/include/asm/hvm/io.h
+++ b/xen/arch/x86/include/asm/hvm/io.h
@@ -132,9 +132,6 @@ int register_vpci_mmcfg_handler(struct domain *d, paddr_t
addr,
/* Destroy tracked MMCFG areas. */
void destroy_vpci_mmcfg(struct domain *d);
-/* Remove MMCFG regions from a given rangeset. */
-int vpci_subtract_mmcfg(const struct domain *d, struct rangeset *r);
-
#endif /* __ASM_X86_HVM_IO_H__ */
diff --git a/xen/drivers/passthrough/x86/iommu.c
b/xen/drivers/passthrough/x86/iommu.c
index 8b1e0596b84a..3b386eb19d13 100644
--- a/xen/drivers/passthrough/x86/iommu.c
+++ b/xen/drivers/passthrough/x86/iommu.c
@@ -320,6 +320,26 @@ static int __hwdom_init cf_check map_subtract(unsigned
long s, unsigned long e,
return rangeset_remove_range(map, s, e);
}
+struct handle_iomemcap {
+ struct rangeset *r;
+ unsigned long last;
+};
+static int __hwdom_init cf_check map_subtract_iomemcap(unsigned long s,
+ unsigned long e,
+ void *data)
+{
+ struct handle_iomemcap *h = data;
+ int rc = 0;
+
+ if ( h->last != s )
+ rc = rangeset_remove_range(h->r, h->last, s - 1);
+
+ /* Be careful with overflows. */
+ h->last = max(e + 1, e);
+
+ return rc;
+}
+
struct map_data {
struct domain *d;
unsigned int flush_flags;
@@ -400,6 +420,7 @@ void __hwdom_init arch_iommu_hwdom_init(struct domain *d)
unsigned int i;
struct rangeset *map;
struct map_data map_data = { .d = d };
+ struct handle_iomemcap iomem = {};
int rc;
BUG_ON(!is_hardware_domain(d));
@@ -442,14 +463,6 @@ void __hwdom_init arch_iommu_hwdom_init(struct domain *d)
switch ( entry.type )
{
- case E820_UNUSABLE:
- /* Only relevant for inclusive mode, otherwise this is a no-op. */
- rc = rangeset_remove_range(map, PFN_DOWN(entry.addr),
- PFN_DOWN(entry.addr + entry.size - 1));
- if ( rc )
- panic("IOMMU failed to remove unusable memory: %d\n", rc);
- continue;
-
case E820_RESERVED:
if ( !iommu_hwdom_inclusive && !iommu_hwdom_reserved )
continue;
@@ -475,22 +488,13 @@ void __hwdom_init arch_iommu_hwdom_init(struct domain *d)
if ( rc )
panic("IOMMU failed to remove Xen ranges: %d\n", rc);
- /* Remove any overlap with the Interrupt Address Range. */
- rc = rangeset_remove_range(map, 0xfee00, 0xfeeff);
+ iomem.r = map;
+ rc = rangeset_report_ranges(d->iomem_caps, 0, ~0UL, map_subtract_iomemcap,
+ &iomem);
+ if ( !rc && iomem.last < ~0UL )
+ rc = rangeset_remove_range(map, iomem.last, ~0UL);
if ( rc )
- panic("IOMMU failed to remove Interrupt Address Range: %d\n", rc);
-
- /* If emulating IO-APIC(s) make sure the base address is unmapped. */
- if ( has_vioapic(d) )
- {
- for ( i = 0; i < d->arch.hvm.nr_vioapics; i++ )
- {
- rc = rangeset_remove_singleton(map,
- PFN_DOWN(domain_vioapic(d, i)->base_address));
- if ( rc )
- panic("IOMMU failed to remove IO-APIC: %d\n", rc);
- }
- }
+ panic("IOMMU failed to remove forbidden regions: %d\n", rc);
if ( is_pv_domain(d) )
{
@@ -506,17 +510,6 @@ void __hwdom_init arch_iommu_hwdom_init(struct domain *d)
panic("IOMMU failed to remove read-only regions: %d\n", rc);
}
- if ( has_vpci(d) )
- {
- /*
- * TODO: runtime added MMCFG regions are not checked to make sure they
- * don't overlap with already mapped regions, thus preventing trapping.
- */
- rc = vpci_subtract_mmcfg(d, map);
- if ( rc )
- panic("IOMMU unable to remove MMCFG areas: %d\n", rc);
- }
-
/* Remove any regions past the last address addressable by the domain. */
rc = rangeset_remove_range(map, PFN_DOWN(1UL << domain_max_paddr_bits(d)),
~0UL);
--
2.46.0
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