This makes use of a new VFIO_REGION_INFO_CAP_MSIX_MAPPABLE capability which tells that a region with MSIX data can be mapped entirely, i.e. the VFIO PCI driver won't prevent MSIX vectors area from being mapped.
With this change, all BARs are mapped in a single chunk and MSIX vectors are emulated on top unless the machine requests not to by defining and enabling a new "vfio-no-msix-emulation" property. At the moment only sPAPR machine does so - it prohibits MSIX emulation and does not allow enabling it as it does not define the "set" callback for the new property; the new property also does not appear in "-machine pseries,help". If MSIX vectors section is not aligned to the page size, the KVM memory listener does not register it with the KVM as a memory slot and MSIX is emulated by QEMU as before. This may create MMIO RAM memory sections with an address or/and a size not aligned which will make vfio_dma_map() fail; to address this, this treats such failures as non-fatal and does not print an error. This adds a return value from vfio_dma_map() to the tracepoint and moves the latter further down to let the user have a clue why P2P might not work. This requires the kernel change - "vfio-pci: Allow mapping MSIX BAR" - for the new capability: https://www.spinics.net/lists/kvm/msg160282.html Signed-off-by: Alexey Kardashevskiy <a...@ozlabs.ru> --- Changes: v4: * silenced dma map errors if unaligned mapping is attempted - they are going to fail anyway v3: * vfio_listener_region_add() won't make qemu exit if failed on MMIO MR --- include/hw/vfio/vfio-common.h | 1 + linux-headers/linux/vfio.h | 5 +++++ hw/ppc/spapr.c | 7 +++++++ hw/vfio/common.c | 27 +++++++++++++++++++++++++-- hw/vfio/pci.c | 10 ++++++++++ hw/vfio/trace-events | 2 +- 6 files changed, 49 insertions(+), 3 deletions(-) diff --git a/include/hw/vfio/vfio-common.h b/include/hw/vfio/vfio-common.h index f3a2ac9..927d600 100644 --- a/include/hw/vfio/vfio-common.h +++ b/include/hw/vfio/vfio-common.h @@ -171,6 +171,7 @@ int vfio_get_region_info(VFIODevice *vbasedev, int index, struct vfio_region_info **info); int vfio_get_dev_region_info(VFIODevice *vbasedev, uint32_t type, uint32_t subtype, struct vfio_region_info **info); +bool vfio_is_cap_present(VFIODevice *vbasedev, uint16_t cap_type, int region); #endif extern const MemoryListener vfio_prereg_listener; diff --git a/linux-headers/linux/vfio.h b/linux-headers/linux/vfio.h index 4312e96..b45182e 100644 --- a/linux-headers/linux/vfio.h +++ b/linux-headers/linux/vfio.h @@ -301,6 +301,11 @@ struct vfio_region_info_cap_type { #define VFIO_REGION_SUBTYPE_INTEL_IGD_HOST_CFG (2) #define VFIO_REGION_SUBTYPE_INTEL_IGD_LPC_CFG (3) +/* + * The MSIX mappable capability informs that MSIX data of a BAR can be mmapped. + */ +#define VFIO_REGION_INFO_CAP_MSIX_MAPPABLE 3 + /** * VFIO_DEVICE_GET_IRQ_INFO - _IOWR(VFIO_TYPE, VFIO_BASE + 9, * struct vfio_irq_info) diff --git a/hw/ppc/spapr.c b/hw/ppc/spapr.c index d1acfe8..5ff43ce 100644 --- a/hw/ppc/spapr.c +++ b/hw/ppc/spapr.c @@ -2789,6 +2789,11 @@ static void spapr_set_modern_hotplug_events(Object *obj, bool value, spapr->use_hotplug_event_source = value; } +static bool spapr_get_msix_emulation(Object *obj, Error **errp) +{ + return true; +} + static char *spapr_get_resize_hpt(Object *obj, Error **errp) { sPAPRMachineState *spapr = SPAPR_MACHINE(obj); @@ -2870,6 +2875,8 @@ static void spapr_instance_init(Object *obj) object_property_set_description(obj, "vsmt", "Virtual SMT: KVM behaves as if this were" " the host's SMT mode", &error_abort); + object_property_add_bool(obj, "vfio-no-msix-emulation", + spapr_get_msix_emulation, NULL, NULL); } static void spapr_machine_finalizefn(Object *obj) diff --git a/hw/vfio/common.c b/hw/vfio/common.c index 3d652c8..04a8280 100644 --- a/hw/vfio/common.c +++ b/hw/vfio/common.c @@ -513,13 +513,21 @@ static void vfio_listener_region_add(MemoryListener *listener, section->offset_within_region + (iova - section->offset_within_address_space); - trace_vfio_listener_region_add_ram(iova, end, vaddr); - llsize = int128_sub(llend, int128_make64(iova)); ret = vfio_dma_map(container, iova, int128_get64(llsize), vaddr, section->readonly); + trace_vfio_listener_region_add_ram(iova, end, vaddr, ret); + if (ret) { + hwaddr pgmask = (1ULL << ctz64(hostwin->iova_pgsizes)) - 1; + + if (memory_region_is_ram_device(section->mr) && + ((section->offset_within_region & pgmask) || + (int128_getlo(section->size) & pgmask))) { + return; + } + error_report("vfio_dma_map(%p, 0x%"HWADDR_PRIx", " "0x%"HWADDR_PRIx", %p) = %d (%m)", container, iova, int128_get64(llsize), vaddr, ret); @@ -1386,6 +1394,21 @@ int vfio_get_dev_region_info(VFIODevice *vbasedev, uint32_t type, return -ENODEV; } +bool vfio_is_cap_present(VFIODevice *vbasedev, uint16_t cap_type, int region) +{ + struct vfio_region_info *info = NULL; + bool ret = false; + + if (!vfio_get_region_info(vbasedev, region, &info)) { + if (vfio_get_region_info_cap(info, cap_type)) { + ret = true; + } + g_free(info); + } + + return ret; +} + /* * Interfaces for IBM EEH (Enhanced Error Handling) */ diff --git a/hw/vfio/pci.c b/hw/vfio/pci.c index 359a8f1..a96ece6 100644 --- a/hw/vfio/pci.c +++ b/hw/vfio/pci.c @@ -1289,6 +1289,11 @@ static void vfio_pci_fixup_msix_region(VFIOPCIDevice *vdev) off_t start, end; VFIORegion *region = &vdev->bars[vdev->msix->table_bar].region; + if (vfio_is_cap_present(&vdev->vbasedev, VFIO_REGION_INFO_CAP_MSIX_MAPPABLE, + vdev->msix->table_bar)) { + return; + } + /* * We expect to find a single mmap covering the whole BAR, anything else * means it's either unsupported or already setup. @@ -1569,6 +1574,11 @@ static int vfio_msix_setup(VFIOPCIDevice *vdev, int pos, Error **errp) */ memory_region_set_enabled(&vdev->pdev.msix_pba_mmio, false); + if (object_property_get_bool(OBJECT(qdev_get_machine()), + "vfio-no-msix-emulation", NULL)) { + memory_region_set_enabled(&vdev->pdev.msix_table_mmio, false); + } + return 0; } diff --git a/hw/vfio/trace-events b/hw/vfio/trace-events index 437ccdd..d747c11 100644 --- a/hw/vfio/trace-events +++ b/hw/vfio/trace-events @@ -89,7 +89,7 @@ vfio_region_read(char *name, int index, uint64_t addr, unsigned size, uint64_t d vfio_iommu_map_notify(const char *op, uint64_t iova_start, uint64_t iova_end) "iommu %s @ 0x%"PRIx64" - 0x%"PRIx64 vfio_listener_region_add_skip(uint64_t start, uint64_t end) "SKIPPING region_add 0x%"PRIx64" - 0x%"PRIx64 vfio_listener_region_add_iommu(uint64_t start, uint64_t end) "region_add [iommu] 0x%"PRIx64" - 0x%"PRIx64 -vfio_listener_region_add_ram(uint64_t iova_start, uint64_t iova_end, void *vaddr) "region_add [ram] 0x%"PRIx64" - 0x%"PRIx64" [%p]" +vfio_listener_region_add_ram(uint64_t iova_start, uint64_t iova_end, void *vaddr, int ret) "region_add [ram] 0x%"PRIx64" - 0x%"PRIx64" [%p] ret=%d" vfio_listener_region_del_skip(uint64_t start, uint64_t end) "SKIPPING region_del 0x%"PRIx64" - 0x%"PRIx64 vfio_listener_region_del(uint64_t start, uint64_t end) "region_del 0x%"PRIx64" - 0x%"PRIx64 vfio_disconnect_container(int fd) "close container->fd=%d" -- 2.11.0
