From 4c70875372b821b045e84f462466a5c04b091ef5 Mon Sep 17 00:00:00 2001 From: Jason Wang Date: Wed, 9 Sep 2020 16:17:31 +0800 Subject: [PATCH] pci: advertise a page aligned ATS After Linux kernel commit 61363c1474b1 ("iommu/vt-d: Enable ATS only if the device uses page aligned address."), ATS will be only enabled if device advertises a page aligned request. Unfortunately, vhost-net is the only user and we don't advertise the aligned request capability in the past since both vhost IOTLB and address_space_get_iotlb_entry() can support non page aligned request. Though it's not clear that if the above kernel commit makes sense. Let's advertise a page aligned ATS here to make vhost device IOTLB work with Intel IOMMU again. Note that in the future we may extend pcie_ats_init() to accept parameters like queue depth and page alignment. Cc: qemu-stable@nongnu.org Signed-off-by: Jason Wang Message-Id: <20200909081731.24688-1-jasowang@redhat.com> Reviewed-by: Peter Xu Reviewed-by: Michael S. Tsirkin Signed-off-by: Michael S. Tsirkin --- hw/pci/pcie.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) diff --git a/hw/pci/pcie.c b/hw/pci/pcie.c index 5b48bae0f6..d4010cf8f3 100644 --- a/hw/pci/pcie.c +++ b/hw/pci/pcie.c @@ -971,8 +971,9 @@ void pcie_ats_init(PCIDevice *dev, uint16_t offset) dev->exp.ats_cap = offset; - /* Invalidate Queue Depth 0, Page Aligned Request 0 */ - pci_set_word(dev->config + offset + PCI_ATS_CAP, 0); + /* Invalidate Queue Depth 0, Page Aligned Request 1 */ + pci_set_word(dev->config + offset + PCI_ATS_CAP, + PCI_ATS_CAP_PAGE_ALIGNED); /* STU 0, Disabled by default */ pci_set_word(dev->config + offset + PCI_ATS_CTRL, 0);