[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]
Message-ID: <20230729013535.1070024-4-seanjc@google.com>
Date: Fri, 28 Jul 2023 18:35:09 -0700
From: Sean Christopherson <seanjc@...gle.com>
To: Sean Christopherson <seanjc@...gle.com>,
Paolo Bonzini <pbonzini@...hat.com>,
Zhenyu Wang <zhenyuw@...ux.intel.com>,
Zhi Wang <zhi.a.wang@...el.com>
Cc: kvm@...r.kernel.org, intel-gvt-dev@...ts.freedesktop.org,
intel-gfx@...ts.freedesktop.org, linux-kernel@...r.kernel.org,
Yan Zhao <yan.y.zhao@...el.com>,
Yongwei Ma <yongwei.ma@...el.com>,
Ben Gardon <bgardon@...gle.com>
Subject: [PATCH v4 03/29] drm/i915/gvt: Verify hugepages are contiguous in
physical address space
When shadowing a GTT entry with a 2M page, verify that the pfns are
contiguous, not just that the struct page pointers are contiguous. The
memory map is virtual contiguous if "CONFIG_FLATMEM=y ||
CONFIG_SPARSEMEM_VMEMMAP=y", but not for "CONFIG_SPARSEMEM=y &&
CONFIG_SPARSEMEM_VMEMMAP=n", so theoretically KVMGT could encounter struct
pages that are virtually contiguous, but not physically contiguous.
In practice, this flaw is likely a non-issue as it would cause functional
problems iff a section isn't 2M aligned _and_ is directly adjacent to
another section with discontiguous pfns.
Tested-by: Yongwei Ma <yongwei.ma@...el.com>
Signed-off-by: Sean Christopherson <seanjc@...gle.com>
---
drivers/gpu/drm/i915/gvt/kvmgt.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/gpu/drm/i915/gvt/kvmgt.c b/drivers/gpu/drm/i915/gvt/kvmgt.c
index de675d799c7d..429f0f993a13 100644
--- a/drivers/gpu/drm/i915/gvt/kvmgt.c
+++ b/drivers/gpu/drm/i915/gvt/kvmgt.c
@@ -161,7 +161,7 @@ static int gvt_pin_guest_page(struct intel_vgpu *vgpu, unsigned long gfn,
if (npage == 0)
base_page = cur_page;
- else if (base_page + npage != cur_page) {
+ else if (page_to_pfn(base_page) + npage != page_to_pfn(cur_page)) {
gvt_vgpu_err("The pages are not continuous\n");
ret = -EINVAL;
npage++;
--
2.41.0.487.g6d72f3e995-goog
Powered by blists - more mailing lists