File xsa400-08.patch of Package xen.26345
IOMMU/x86: maintain a per-device pseudo domain ID
In order to subsequently enable per-device quarantine page tables, we'll
need domain-ID-like identifiers to be inserted in the respective device
(AMD) or context (Intel) table entries alongside the per-device page
table root addresses.
Make use of "real" domain IDs occupying only half of the value range
coverable by domid_t.
Note that in VT-d's iommu_alloc() I didn't want to introduce new memory
leaks in case of error, but existing ones don't get plugged - that'll be
the subject of a later change.
The VT-d changes are slightly asymmetric, but this way we can avoid
assigning pseudo domain IDs to devices which would never be mapped while
still avoiding to add a new parameter to domain_context_unmap().
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Reviewed-by: Paul Durrant <paul@xen.org>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Reviewed-by: Roger Pau Monné <roger.pau@citrix.com>
--- a/xen/include/asm-x86/iommu.h
+++ b/xen/include/asm-x86/iommu.h
@@ -112,6 +112,10 @@ int pi_update_irte(const struct pi_desc
ops->sync_cache(addr, size); \
})
+unsigned long *iommu_init_domid(void);
+domid_t iommu_alloc_domid(unsigned long *map);
+void iommu_free_domid(domid_t domid, unsigned long *map);
+
#endif /* !__ARCH_X86_IOMMU_H__ */
/*
* Local variables:
--- a/xen/include/asm-x86/pci.h
+++ b/xen/include/asm-x86/pci.h
@@ -13,6 +13,12 @@
struct arch_pci_dev {
vmask_t used_vectors;
+ /*
+ * These fields are (de)initialized under pcidevs-lock. Other uses of
+ * them don't race (de)initialization and hence don't strictly need any
+ * locking.
+ */
+ domid_t pseudo_domid;
};
int pci_conf_write_intercept(unsigned int seg, unsigned int bdf,
--- a/xen/include/asm-x86/amd-iommu.h
+++ b/xen/include/asm-x86/amd-iommu.h
@@ -97,6 +97,7 @@ struct amd_iommu {
struct ring_buffer cmd_buffer;
struct ring_buffer event_log;
struct ring_buffer ppr_log;
+ unsigned long *domid_map;
int exclusion_enable;
int exclusion_allow_all;
--- a/xen/drivers/passthrough/amd/iommu_detect.c
+++ b/xen/drivers/passthrough/amd/iommu_detect.c
@@ -150,6 +150,11 @@ int __init amd_iommu_detect_one_acpi(
if ( rt )
goto out;
+ iommu->domid_map = iommu_init_domid();
+ rt = -ENOMEM;
+ if ( !iommu->domid_map )
+ goto out;
+
rt = pci_ro_device(iommu->seg, bus, PCI_DEVFN(dev, func));
if ( rt )
printk(XENLOG_ERR
@@ -161,7 +166,10 @@ int __init amd_iommu_detect_one_acpi(
out:
if ( rt )
+ {
+ xfree(iommu->domid_map);
xfree(iommu);
+ }
return rt;
}
--- a/xen/drivers/passthrough/amd/pci_amd_iommu.c
+++ b/xen/drivers/passthrough/amd/pci_amd_iommu.c
@@ -567,6 +567,8 @@ static int amd_iommu_add_device(u8 devfn
{
struct amd_iommu *iommu;
u16 bdf;
+ bool fresh_domid = false;
+ int ret;
if ( !pdev->domain )
return -EINVAL;
@@ -591,7 +593,22 @@ static int amd_iommu_add_device(u8 devfn
return -ENODEV;
}
- return amd_iommu_setup_domain_device(pdev->domain, iommu, devfn, pdev);
+ if ( iommu_quarantine && pdev->arch.pseudo_domid == DOMID_INVALID )
+ {
+ pdev->arch.pseudo_domid = iommu_alloc_domid(iommu->domid_map);
+ if ( pdev->arch.pseudo_domid == DOMID_INVALID )
+ return -ENOSPC;
+ fresh_domid = true;
+ }
+
+ ret = amd_iommu_setup_domain_device(pdev->domain, iommu, devfn, pdev);
+ if ( ret && fresh_domid )
+ {
+ iommu_free_domid(pdev->arch.pseudo_domid, iommu->domid_map);
+ pdev->arch.pseudo_domid = DOMID_INVALID;
+ }
+
+ return ret;
}
static int amd_iommu_remove_device(u8 devfn, struct pci_dev *pdev)
@@ -613,6 +630,10 @@ static int amd_iommu_remove_device(u8 de
}
amd_iommu_disable_domain_device(pdev->domain, iommu, devfn, pdev);
+
+ iommu_free_domid(pdev->arch.pseudo_domid, iommu->domid_map);
+ pdev->arch.pseudo_domid = DOMID_INVALID;
+
return 0;
}
--- a/xen/drivers/passthrough/pci.c
+++ b/xen/drivers/passthrough/pci.c
@@ -313,6 +313,7 @@ static struct pci_dev *alloc_pdev(struct
*((u8*) &pdev->bus) = bus;
*((u8*) &pdev->devfn) = devfn;
pdev->domain = NULL;
+ pdev->arch.pseudo_domid = DOMID_INVALID;
INIT_LIST_HEAD(&pdev->msi_list);
if ( pci_find_cap_offset(pseg->nr, bus, PCI_SLOT(devfn), PCI_FUNC(devfn),
@@ -1238,10 +1239,13 @@ static int _dump_pci_devices(struct pci_
list_for_each_entry ( pdev, &pseg->alldevs_list, alldevs_list )
{
- printk("%04x:%02x:%02x.%u - dom %-3d - node %-3d - MSIs < ",
- pseg->nr, pdev->bus,
- PCI_SLOT(pdev->devfn), PCI_FUNC(pdev->devfn),
- pdev->domain ? pdev->domain->domain_id : -1,
+ printk("%04x:%02x:%02x.%u - ", pseg->nr, pdev->bus,
+ PCI_SLOT(pdev->devfn), PCI_FUNC(pdev->devfn));
+ if ( pdev->domain == dom_io )
+ printk("DomIO:%x", pdev->arch.pseudo_domid);
+ else if ( pdev->domain )
+ printk("Dom%d", pdev->domain->domain_id);
+ printk(" - node %-3d - MSIs < ",
(pdev->node != NUMA_NO_NODE) ? pdev->node : -1);
list_for_each_entry ( msi, &pdev->msi_list, list )
printk("%d ", msi->irq);
--- a/xen/drivers/passthrough/vtd/iommu.c
+++ b/xen/drivers/passthrough/vtd/iommu.c
@@ -22,6 +22,7 @@
#include <xen/sched.h>
#include <xen/xmalloc.h>
#include <xen/domain_page.h>
+#include <xen/err.h>
#include <xen/iocap.h>
#include <xen/iommu.h>
#include <xen/numa.h>
@@ -1222,7 +1223,7 @@ int __init iommu_alloc(struct acpi_drhd_
{
struct iommu *iommu;
unsigned long sagaw, nr_dom;
- int agaw;
+ int agaw, rc;
if ( nr_iommus > MAX_IOMMUS )
{
@@ -1312,10 +1313,19 @@ int __init iommu_alloc(struct acpi_drhd_
if ( !iommu->domid_map )
return -ENOMEM ;
+ iommu->pseudo_domid_map = iommu_init_domid();
+ rc = -ENOMEM;
+ if ( !iommu->pseudo_domid_map )
+ goto free;
+
spin_lock_init(&iommu->lock);
spin_lock_init(&iommu->register_lock);
return 0;
+
+ free:
+ iommu_free(drhd);
+ return rc;
}
void __init iommu_free(struct acpi_drhd_unit *drhd)
@@ -1338,6 +1348,7 @@ void __init iommu_free(struct acpi_drhd_
xfree(iommu->domid_bitmap);
xfree(iommu->domid_map);
+ xfree(iommu->pseudo_domid_map);
free_intel_iommu(iommu->intel);
if ( iommu->msi.irq >= 0 )
@@ -1618,8 +1629,8 @@ int domain_context_mapping_one(
return rc ?: pdev && prev_dom;
}
-static int domain_context_unmap(struct domain *d, uint8_t devfn,
- struct pci_dev *pdev);
+static const struct acpi_drhd_unit *domain_context_unmap(
+ struct domain *d, uint8_t devfn, struct pci_dev *pdev);
static int domain_context_mapping(struct domain *domain, u8 devfn,
struct pci_dev *pdev)
@@ -1627,6 +1638,7 @@ static int domain_context_mapping(struct
struct acpi_drhd_unit *drhd;
const struct acpi_rmrr_unit *rmrr;
paddr_t pgd_maddr = dom_iommu(domain)->arch.pgd_maddr;
+ domid_t orig_domid = pdev->arch.pseudo_domid;
int ret = 0;
unsigned int i, mode = 0;
uint16_t seg = pdev->seg, bdf;
@@ -1677,6 +1689,14 @@ static int domain_context_mapping(struct
break;
case DEV_TYPE_PCIe_ENDPOINT:
+ if ( iommu_quarantine && orig_domid == DOMID_INVALID )
+ {
+ pdev->arch.pseudo_domid =
+ iommu_alloc_domid(drhd->iommu->pseudo_domid_map);
+ if ( pdev->arch.pseudo_domid == DOMID_INVALID )
+ return -ENOSPC;
+ }
+
if ( iommu_debug )
printk(VTDPREFIX "d%d:PCIe: map %04x:%02x:%02x.%u\n",
domain->domain_id, seg, bus,
@@ -1692,6 +1712,14 @@ static int domain_context_mapping(struct
break;
case DEV_TYPE_PCI:
+ if ( iommu_quarantine && orig_domid == DOMID_INVALID )
+ {
+ pdev->arch.pseudo_domid =
+ iommu_alloc_domid(drhd->iommu->pseudo_domid_map);
+ if ( pdev->arch.pseudo_domid == DOMID_INVALID )
+ return -ENOSPC;
+ }
+
if ( iommu_debug )
printk(VTDPREFIX "d%d:PCI: map %04x:%02x:%02x.%u\n",
domain->domain_id, seg, bus,
@@ -1765,6 +1793,13 @@ static int domain_context_mapping(struct
if ( !ret && devfn == pdev->devfn )
pci_vtd_quirk(pdev);
+ if ( ret && drhd && orig_domid == DOMID_INVALID )
+ {
+ iommu_free_domid(pdev->arch.pseudo_domid,
+ drhd->iommu->pseudo_domid_map);
+ pdev->arch.pseudo_domid = DOMID_INVALID;
+ }
+
return ret;
}
@@ -1834,8 +1869,10 @@ int domain_context_unmap_one(
return rc;
}
-static int domain_context_unmap(struct domain *domain, u8 devfn,
- struct pci_dev *pdev)
+static const struct acpi_drhd_unit *domain_context_unmap(
+ struct domain *domain,
+ uint8_t devfn,
+ struct pci_dev *pdev)
{
struct acpi_drhd_unit *drhd;
struct iommu *iommu;
@@ -1844,7 +1881,7 @@ static int domain_context_unmap(struct d
drhd = acpi_find_matched_drhd_unit(pdev);
if ( !drhd )
- return -ENODEV;
+ return ERR_PTR(-ENODEV);
iommu = drhd->iommu;
switch ( pdev->type )
@@ -1855,7 +1892,7 @@ static int domain_context_unmap(struct d
domain->domain_id, seg, bus,
PCI_SLOT(devfn), PCI_FUNC(devfn));
if ( !is_hardware_domain(domain) )
- return -EPERM;
+ return ERR_PTR(-EPERM);
goto out;
case DEV_TYPE_PCIe_BRIDGE:
@@ -1894,11 +1931,9 @@ static int domain_context_unmap(struct d
{
ret = domain_context_unmap_one(domain, iommu, tmp_bus, tmp_devfn,
domain->domain_id);
- if ( ret )
- return ret;
-
- ret = domain_context_unmap_one(domain, iommu, secbus, 0,
- domain->domain_id);
+ if ( !ret )
+ ret = domain_context_unmap_one(domain, iommu, secbus, 0,
+ domain->domain_id);
}
else /* Legacy PCI bridge */
ret = domain_context_unmap_one(domain, iommu, tmp_bus, tmp_devfn,
@@ -1918,7 +1953,7 @@ static int domain_context_unmap(struct d
check_cleanup_domid_map(domain, pdev, iommu);
out:
- return ret;
+ return ret ? ERR_PTR(ret) : drhd;
}
static void iommu_domain_teardown(struct domain *d)
@@ -2098,16 +2133,17 @@ static int intel_iommu_enable_device(str
static int intel_iommu_remove_device(u8 devfn, struct pci_dev *pdev)
{
+ const struct acpi_drhd_unit *drhd;
struct acpi_rmrr_unit *rmrr;
u16 bdf;
- int ret, i;
+ unsigned int i;
if ( !pdev->domain )
return -EINVAL;
- ret = domain_context_unmap(pdev->domain, devfn, pdev);
- if ( ret )
- return ret;
+ drhd = domain_context_unmap(pdev->domain, devfn, pdev);
+ if ( IS_ERR(drhd) )
+ return PTR_ERR(drhd);
for_each_rmrr_device ( rmrr, bdf, i )
{
@@ -2124,6 +2160,13 @@ static int intel_iommu_remove_device(u8
rmrr->end_address, 0);
}
+ if ( drhd )
+ {
+ iommu_free_domid(pdev->arch.pseudo_domid,
+ drhd->iommu->pseudo_domid_map);
+ pdev->arch.pseudo_domid = DOMID_INVALID;
+ }
+
return 0;
}
--- a/xen/drivers/passthrough/vtd/iommu.h
+++ b/xen/drivers/passthrough/vtd/iommu.h
@@ -538,6 +538,7 @@ struct iommu {
struct msi_desc msi;
struct intel_iommu *intel;
struct list_head ats_devices;
+ unsigned long *pseudo_domid_map; /* "pseudo" domain id bitmap */
unsigned long *domid_bitmap; /* domain id bitmap */
u16 *domid_map; /* domain id mapping array */
};
--- a/xen/drivers/passthrough/x86/iommu.c
+++ b/xen/drivers/passthrough/x86/iommu.c
@@ -246,6 +246,53 @@ void iommu_identity_map_teardown(struct
}
}
+unsigned long *__init iommu_init_domid(void)
+{
+ if ( !iommu_quarantine )
+ return ZERO_BLOCK_PTR;
+
+ BUILD_BUG_ON(DOMID_MASK * 2U >= UINT16_MAX);
+
+ return xzalloc_array(unsigned long,
+ BITS_TO_LONGS(UINT16_MAX - DOMID_MASK));
+}
+
+domid_t iommu_alloc_domid(unsigned long *map)
+{
+ /*
+ * This is used uniformly across all IOMMUs, such that on typical
+ * systems we wouldn't re-use the same ID very quickly (perhaps never).
+ */
+ static unsigned int start;
+ unsigned int idx = find_next_zero_bit(map, UINT16_MAX - DOMID_MASK, start);
+
+ ASSERT(pcidevs_locked());
+
+ if ( idx >= UINT16_MAX - DOMID_MASK )
+ idx = find_first_zero_bit(map, UINT16_MAX - DOMID_MASK);
+ if ( idx >= UINT16_MAX - DOMID_MASK )
+ return DOMID_INVALID;
+
+ __set_bit(idx, map);
+
+ start = idx + 1;
+
+ return idx | (DOMID_MASK + 1);
+}
+
+void iommu_free_domid(domid_t domid, unsigned long *map)
+{
+ ASSERT(pcidevs_locked());
+
+ if ( domid == DOMID_INVALID )
+ return;
+
+ ASSERT(domid > DOMID_MASK);
+
+ if ( !__test_and_clear_bit(domid & DOMID_MASK, map) )
+ BUG();
+}
+
/*
* Local variables:
* mode: C
--- a/xen/include/public/xen.h
+++ b/xen/include/public/xen.h
@@ -578,6 +578,9 @@ DEFINE_XEN_GUEST_HANDLE(mmuext_op_t);
/* Idle domain. */
#define DOMID_IDLE xen_mk_uint(0x7FFF)
+/* Mask for valid domain id values */
+#define DOMID_MASK xen_mk_uint(0x7FFF)
+
#ifndef __ASSEMBLY__
typedef uint16_t domid_t;
