From: Malcolm Crossley Date: Tue, 24 Jun 2014 08:23:12 +0000 (+0200) Subject: IOMMU: prevent VT-d device IOTLB operations on wrong IOMMU X-Git-Tag: 4.2.5-rc2~10 X-Git-Url: http://xenbits.xensource.com/gitweb?a=commitdiff_plain;h=e58d4039d408f8b9342fa5a20a515b9a1909a313;p=xen.git IOMMU: prevent VT-d device IOTLB operations on wrong IOMMU PCIe ATS allows for devices to contain IOTLBs, the VT-d code was iterating around all ATS capable devices and issuing IOTLB operations for all IOMMUs, even though each ATS device is only accessible via one particular IOMMU. Issuing an IOMMU operation to a device not accessible via that IOMMU results in an IOMMU timeout because the device does not reply. VT-d IOMMU timeouts result in a Xen panic. Therefore this bug prevents any Intel system with 2 or more ATS enabled IOMMUs, each with an ATS device connected to them, from booting Xen. The patch adds a IOMMU pointer to the ATS device struct so the VT-d code can ensure it does not issue IOMMU ATS operations on the wrong IOMMU. A void pointer has to be used because AMD and Intel IOMMU implementations do not have a common IOMMU structure or indexing mechanism. Signed-off-by: Malcolm Crossley Reviewed-by: Andrew Cooper Acked-by: Kevin Tian Reviewed-by: Jan Beulich master commit: 84c340ba4c3eb99278b6ba885616bb183b88ad67 master date: 2014-06-18 15:50:02 +0200 --- diff --git a/xen/drivers/passthrough/amd/pci_amd_iommu.c b/xen/drivers/passthrough/amd/pci_amd_iommu.c index c3cbf887fe..75b323bb29 100644 --- a/xen/drivers/passthrough/amd/pci_amd_iommu.c +++ b/xen/drivers/passthrough/amd/pci_amd_iommu.c @@ -137,7 +137,7 @@ static void amd_iommu_setup_domain_device( { struct pci_dev *pdev; - enable_ats_device(iommu->seg, bus, devfn); + enable_ats_device(iommu->seg, bus, devfn, iommu); ASSERT(spin_is_locked(&pcidevs_lock)); pdev = pci_get_pdev(iommu->seg, bus, devfn); diff --git a/xen/drivers/passthrough/ats.h b/xen/drivers/passthrough/ats.h index c34fa2cad5..cf082afcc5 100644 --- a/xen/drivers/passthrough/ats.h +++ b/xen/drivers/passthrough/ats.h @@ -24,6 +24,7 @@ struct pci_ats_dev { u8 bus; u8 devfn; u16 ats_queue_depth; /* ATS device invalidation queue depth */ + const void *iommu; /* No common IOMMU struct so use void pointer */ }; #ifdef CONFIG_X86_64 @@ -36,7 +37,7 @@ struct pci_ats_dev { extern struct list_head ats_devices; extern bool_t ats_enabled; -int enable_ats_device(int seg, int bus, int devfn); +int enable_ats_device(int seg, int bus, int devfn, const void *iommu); void disable_ats_device(int seg, int bus, int devfn); struct pci_ats_dev *get_ats_device(int seg, int bus, int devfn); @@ -64,7 +65,7 @@ static inline int pci_ats_device(int seg, int bus, int devfn) #else #define ats_enabled 0 -static inline int enable_ats_device(int seg, int bus, int devfn) +static inline int enable_ats_device(int seg, int bus, int devfn, const void *iommu) { BUG(); return -ENOSYS; diff --git a/xen/drivers/passthrough/vtd/iommu.c b/xen/drivers/passthrough/vtd/iommu.c index bb7c4443d5..51c3f98073 100644 --- a/xen/drivers/passthrough/vtd/iommu.c +++ b/xen/drivers/passthrough/vtd/iommu.c @@ -1475,7 +1475,7 @@ static int domain_context_mapping( PCI_SLOT(devfn), PCI_FUNC(devfn)); ret = domain_context_mapping_one(domain, drhd->iommu, bus, devfn); if ( !ret && ats_device(pdev, drhd) > 0 ) - enable_ats_device(seg, bus, devfn); + enable_ats_device(seg, bus, devfn, drhd->iommu); break; @@ -1961,7 +1961,7 @@ static int intel_iommu_enable_device(struct pci_dev *pdev) if ( ret <= 0 ) return ret; - ret = enable_ats_device(pdev->seg, pdev->bus, pdev->devfn); + ret = enable_ats_device(pdev->seg, pdev->bus, pdev->devfn, drhd->iommu); return ret >= 0 ? 0 : ret; } diff --git a/xen/drivers/passthrough/vtd/x86/ats.c b/xen/drivers/passthrough/vtd/x86/ats.c index f3b8c2d9d3..ea57d7d29f 100644 --- a/xen/drivers/passthrough/vtd/x86/ats.c +++ b/xen/drivers/passthrough/vtd/x86/ats.c @@ -120,6 +120,10 @@ int dev_invalidate_iotlb(struct iommu *iommu, u16 did, { sid = (pdev->bus << 8) | pdev->devfn; + /* Only invalidate devices that belong to this IOMMU */ + if ( pdev->iommu != iommu ) + continue; + switch ( type ) { case DMA_TLB_DSI_FLUSH: if ( !device_in_domain(iommu, pdev, did) ) diff --git a/xen/drivers/passthrough/x86/ats.c b/xen/drivers/passthrough/x86/ats.c index bb7ee9ab68..1e3e03ab40 100644 --- a/xen/drivers/passthrough/x86/ats.c +++ b/xen/drivers/passthrough/x86/ats.c @@ -23,7 +23,7 @@ LIST_HEAD(ats_devices); bool_t __read_mostly ats_enabled = 1; boolean_param("ats", ats_enabled); -int enable_ats_device(int seg, int bus, int devfn) +int enable_ats_device(int seg, int bus, int devfn, const void *iommu) { struct pci_ats_dev *pdev = NULL; u32 value; @@ -66,6 +66,7 @@ int enable_ats_device(int seg, int bus, int devfn) pdev->seg = seg; pdev->bus = bus; pdev->devfn = devfn; + pdev->iommu = iommu; value = pci_conf_read16(seg, bus, PCI_SLOT(devfn), PCI_FUNC(devfn), pos + ATS_REG_CAP); pdev->ats_queue_depth = value & ATS_QUEUE_DEPTH_MASK ?: