[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] Re: [Xen-devel] [PATCH] pvh: change epte_get_entry_emt() for pvh mem types
On 22/11/13 01:00, Mukesh Rathor wrote: For pvh guests, epte_get_entry_emt() is incorrectly returning WB for all mem types because of the following check: if ( !v->domain->arch.hvm_domain.params[HVM_PARAM_IDENT_PT] ) Skip the check for pvh guests. Also note, MTRR ranges are not maintained for pvh, and a solution is being contrived using PAT. Signed-off-by: Mukesh Rathor <mukesh.rathor@xxxxxxxxxx> --- xen/arch/x86/hvm/mtrr.c | 7 ++++++- 1 files changed, 6 insertions(+), 1 deletions(-) diff --git a/xen/arch/x86/hvm/mtrr.c b/xen/arch/x86/hvm/mtrr.c index 4ff1e55..5427e1c 100644 --- a/xen/arch/x86/hvm/mtrr.c +++ b/xen/arch/x86/hvm/mtrr.c @@ -693,7 +693,8 @@ uint8_t epte_get_entry_emt(struct domain *d, unsigned long gfn, mfn_t mfn, ((d->vcpu == NULL) || ((v = d->vcpu[0]) == NULL)) ) return MTRR_TYPE_WRBACK;- if ( !v->domain->arch.hvm_domain.params[HVM_PARAM_IDENT_PT] )+ if ( !is_pvh_vcpu(v) && + !v->domain->arch.hvm_domain.params[HVM_PARAM_IDENT_PT] ) return MTRR_TYPE_WRBACK;if ( !mfn_valid(mfn_x(mfn)) )@@ -717,6 +718,10 @@ uint8_t epte_get_entry_emt(struct domain *d, unsigned long gfn, mfn_t mfn, return MTRR_TYPE_WRBACK; }+ /* MTRR ranges are not maintained for pvh. */+ if ( is_pvh_vcpu(v) ) + return MTRR_TYPE_WRBACK; + gmtrr_mtype = get_mtrr_type(&v->arch.hvm_vcpu.mtrr, (gfn << PAGE_SHIFT)); hmtrr_mtype = get_mtrr_type(&mtrr_state, (mfn_x(mfn) << PAGE_SHIFT)); return ((gmtrr_mtype <= hmtrr_mtype) ? gmtrr_mtype : hmtrr_mtype); So this will bypass the host mtrr settings, and always return WRBACK, even if in mtrr_state it was set to something lower. Presumably that "min(host,guest)" was there for a reason. Are you sure it's safe to just ignore it? This is why I suggested the following instead: gmtrr_mtype = is_hvm_domain(v) ? get_mtrr_type(&v->arch.hvm_vcpu.mtrr, (gfn << PAGE_SHIFT)) : MTRR_TYPE_WRBACK; -George _______________________________________________ Xen-devel mailing list Xen-devel@xxxxxxxxxxxxx http://lists.xen.org/xen-devel
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