From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:44171) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1dGl7e-0008JH-5C for qemu-devel@nongnu.org; Fri, 02 Jun 2017 07:52:07 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1dGl7Z-0007mn-66 for qemu-devel@nongnu.org; Fri, 02 Jun 2017 07:52:06 -0400 Received: from mx1.redhat.com ([209.132.183.28]:53390) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1dGl7Y-0007ma-U5 for qemu-devel@nongnu.org; Fri, 02 Jun 2017 07:52:01 -0400 Received: from smtp.corp.redhat.com (int-mx03.intmail.prod.int.phx2.redhat.com [10.5.11.13]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id E04D47AE81 for ; Fri, 2 Jun 2017 11:51:59 +0000 (UTC) From: Peter Xu Date: Fri, 2 Jun 2017 19:50:54 +0800 Message-Id: <1496404254-17429-4-git-send-email-peterx@redhat.com> In-Reply-To: <1496404254-17429-1-git-send-email-peterx@redhat.com> References: <1496404254-17429-1-git-send-email-peterx@redhat.com> Subject: [Qemu-devel] [PATCH 3/3] vhost: iommu: cache static mapping if there is List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: qemu-devel@nongnu.org Cc: "Michael S . Tsirkin" , Paolo Bonzini , Maxime Coquelin , peterx@redhat.com, Jason Wang This patch pre-heat vhost iotlb cache when passthrough mode enabled. Sometimes, even if user specified iommu_platform for vhost devices, IOMMU might still be disabled. One case is passthrough mode in VT-d implementation. We can detect this by observing iommu_list. If it's empty, it means IOMMU translation is disabled, then we can actually pre-heat the translation (it'll be static mapping then) by first invalidating all IOTLB, then cache existing memory ranges into vhost backend iotlb using 1:1 mapping. Reviewed-by: Jason Wang Signed-off-by: Peter Xu --- hw/virtio/trace-events | 4 +++ hw/virtio/vhost.c | 66 ++++++++++++++++++++++++++++++++++++++++++++++++++ 2 files changed, 70 insertions(+) diff --git a/hw/virtio/trace-events b/hw/virtio/trace-events index 1f7a7c1..54dcbb3 100644 --- a/hw/virtio/trace-events +++ b/hw/virtio/trace-events @@ -24,3 +24,7 @@ virtio_balloon_handle_output(const char *name, uint64_t gpa) "section name: %s g virtio_balloon_get_config(uint32_t num_pages, uint32_t actual) "num_pages: %d actual: %d" virtio_balloon_set_config(uint32_t actual, uint32_t oldactual) "actual: %d oldactual: %d" virtio_balloon_to_target(uint64_t target, uint32_t num_pages) "balloon target: %"PRIx64" num_pages: %d" + +# hw/virtio/vhost.c +vhost_iommu_commit(void) "" +vhost_iommu_static_preheat(void) "" diff --git a/hw/virtio/vhost.c b/hw/virtio/vhost.c index 03a46a7..d03d720 100644 --- a/hw/virtio/vhost.c +++ b/hw/virtio/vhost.c @@ -27,6 +27,7 @@ #include "hw/virtio/virtio-access.h" #include "migration/blocker.h" #include "sysemu/dma.h" +#include "trace.h" /* enabled until disconnected backend stabilizes */ #define _VHOST_DEBUG 1 @@ -730,6 +731,11 @@ static void vhost_iommu_unmap_notify(IOMMUNotifier *n, IOMMUTLBEntry *iotlb) } } +static bool vhost_iommu_mr_enabled(struct vhost_dev *dev) +{ + return !QLIST_EMPTY(&dev->iommu_list); +} + static void vhost_iommu_region_add(MemoryListener *listener, MemoryRegionSection *section) { @@ -782,6 +788,65 @@ static void vhost_iommu_region_del(MemoryListener *listener, } } +static void vhost_iommu_commit(MemoryListener *listener) +{ + struct vhost_dev *dev = container_of(listener, struct vhost_dev, + iommu_listener); + struct vhost_memory_region *r; + int i; + + trace_vhost_iommu_commit(); + + if (!vhost_iommu_mr_enabled(dev)) { + /* + * This means iommu_platform is enabled, however iommu memory + * region is disabled, e.g., when device passthrough is setup. + * Then, no translation is needed any more. + * + * Let's first invalidate the whole IOTLB, then pre-heat the + * static mapping by looping over vhost memory ranges. + */ + + if (dev->vhost_ops->vhost_invalidate_device_iotlb(dev, 0, + UINT64_MAX)) { + error_report("%s: flush existing IOTLB failed", __func__); + return; + } + + /* + * Current VHOST_IOTLB_INVALIDATE API has a small defect that + * the invalidation for (start=0, size=UINT64_MAX) cannot + * really invalidate an cached range of (start=UINT64_MAX-1, + * size=1). We send this 2nd invalidation to workaround this. + * But, frankly speaking for QEMU we don't have a problem with + * this since we will never have a vhost cache with range + * (start=UINT64_MAX-1, size=1) - if you see + * address_space_get_iotlb_entry() all IOTLBs are page + * aligned. + */ + if (dev->vhost_ops->vhost_invalidate_device_iotlb(dev, UINT64_MAX, + 1)) { + error_report("%s: flush existing IOTLB failed", __func__); + return; + } + + for (i = 0; i < dev->mem->nregions; i++) { + r = &dev->mem->regions[i]; + /* Vhost regions are writable RAM, so IOMMU_RW suites. */ + if (dev->vhost_ops->vhost_update_device_iotlb(dev, + r->guest_phys_addr, + r->userspace_addr, + r->memory_size, + IOMMU_RW)) { + error_report("%s: pre-heat static mapping failed", __func__); + return; + } + } + + trace_vhost_iommu_static_preheat(); + } +} + static void vhost_region_nop(MemoryListener *listener, MemoryRegionSection *section) { @@ -1298,6 +1363,7 @@ int vhost_dev_init(struct vhost_dev *hdev, void *opaque, hdev->iommu_listener = (MemoryListener) { .region_add = vhost_iommu_region_add, .region_del = vhost_iommu_region_del, + .commit = vhost_iommu_commit, }; if (hdev->migration_blocker == NULL) { -- 2.7.4