From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Egger, Christoph" Subject: Re: [PATCH] nested EPT: fixing wrong handling for L2 guest's direct mmio access Date: Fri, 17 Jan 2014 09:59:54 +0100 Message-ID: <52D8F10A.7080501@amazon.de> References: <1389940508-2239-1-git-send-email-yang.z.zhang@intel.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <1389940508-2239-1-git-send-email-yang.z.zhang@intel.com> List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Sender: xen-devel-bounces@lists.xen.org Errors-To: xen-devel-bounces@lists.xen.org To: Yang Zhang , xen-devel@lists.xen.org Cc: andrew.cooper3@citrix.com, xiantao.zhang@intel.com, eddie.dong@intel.com, jun.nakajima@intel.com, JBeulich@suse.com List-Id: xen-devel@lists.xenproject.org On 17.01.14 07:35, Yang Zhang wrote: > From: Yang Zhang > > L2 guest will access the physical device directly(nested VT-d). For such access, > Shadow EPT table should point to device's MMIO. But in current logic, L0 doesn't > distinguish the MMIO whether from qemu or physical device when building shadow EPT table. > This is wrong. This patch will setup the correct shadow EPT table for such MMIO ranges. > > Signed-off-by: Yang Zhang > --- > xen/arch/x86/mm/hap/nested_hap.c | 10 ++++++++-- > xen/include/asm-x86/hvm/nestedhvm.h | 1 + > 2 files changed, 9 insertions(+), 2 deletions(-) > > diff --git a/xen/arch/x86/mm/hap/nested_hap.c b/xen/arch/x86/mm/hap/nested_hap.c > index c2ef1d1..38e2327 100644 > --- a/xen/arch/x86/mm/hap/nested_hap.c > +++ b/xen/arch/x86/mm/hap/nested_hap.c > @@ -170,8 +170,11 @@ nestedhap_walk_L0_p2m(struct p2m_domain *p2m, paddr_t L1_gpa, paddr_t *L0_gpa, > mfn = get_gfn_type_access(p2m, L1_gpa >> PAGE_SHIFT, p2mt, p2ma, > 0, page_order); > > + rc = NESTEDHVM_PAGEFAULT_DIRECT_MMIO; > + if ( *p2mt == p2m_mmio_direct ) > + goto direct_mmio_out; > rc = NESTEDHVM_PAGEFAULT_MMIO; > - if ( p2m_is_mmio(*p2mt) ) > + if ( *p2mt == p2m_mmio_dm ) > goto out; Why does p2m_is_mmio() not cover p2m_mmio_direct ? Christoph > rc = NESTEDHVM_PAGEFAULT_L0_ERROR; > @@ -184,8 +187,9 @@ nestedhap_walk_L0_p2m(struct p2m_domain *p2m, paddr_t L1_gpa, paddr_t *L0_gpa, > if ( !mfn_valid(mfn) ) > goto out; > > - *L0_gpa = (mfn_x(mfn) << PAGE_SHIFT) + (L1_gpa & ~PAGE_MASK); > rc = NESTEDHVM_PAGEFAULT_DONE; > +direct_mmio_out: > + *L0_gpa = (mfn_x(mfn) << PAGE_SHIFT) + (L1_gpa & ~PAGE_MASK); > out: > __put_gfn(p2m, L1_gpa >> PAGE_SHIFT); > return rc; > @@ -245,6 +249,8 @@ nestedhvm_hap_nested_page_fault(struct vcpu *v, paddr_t *L2_gpa, > break; > case NESTEDHVM_PAGEFAULT_MMIO: > return rv; > + case NESTEDHVM_PAGEFAULT_DIRECT_MMIO: > + break; > default: > BUG(); > break; > diff --git a/xen/include/asm-x86/hvm/nestedhvm.h b/xen/include/asm-x86/hvm/nestedhvm.h > index d8124cf..cca41b3 100644 > --- a/xen/include/asm-x86/hvm/nestedhvm.h > +++ b/xen/include/asm-x86/hvm/nestedhvm.h > @@ -53,6 +53,7 @@ bool_t nestedhvm_vcpu_in_guestmode(struct vcpu *v); > #define NESTEDHVM_PAGEFAULT_L0_ERROR 3 > #define NESTEDHVM_PAGEFAULT_MMIO 4 > #define NESTEDHVM_PAGEFAULT_RETRY 5 > +#define NESTEDHVM_PAGEFAULT_DIRECT_MMIO 6 > int nestedhvm_hap_nested_page_fault(struct vcpu *v, paddr_t *L2_gpa, > bool_t access_r, bool_t access_w, bool_t access_x); > >