| Message ID | 20230729013535.1070024-4-seanjc@google.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | drm/i915/gvt: KVM: KVMGT fixes and page-track cleanups | expand |
Reviewed-by: Yan Zhao <yan.y.zhao@intel.com> On Fri, Jul 28, 2023 at 06:35:09PM -0700, Sean Christopherson wrote: > 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@intel.com> > Signed-off-by: Sean Christopherson <seanjc@google.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 >
On 8/1/2023 4:47 AM, Yan Zhao wrote: > Reviewed-by: Yan Zhao <yan.y.zhao@intel.com> > > On Fri, Jul 28, 2023 at 06:35:09PM -0700, Sean Christopherson wrote: >> 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@intel.com> >> Signed-off-by: Sean Christopherson <seanjc@google.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 >> Reviewed-by: Zhi Wang <zhi.a.wang@intel.com>
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++;