[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] RE: [Xen-devel] Why CR0.WP is always set in HVM domain
Not sure if we can use shadow_mode_trap_reads(), i.e. when WP is clear, we set all user space mapping to guest page table to be non-present. And then do emulate in shadow for such situation. But seems shadow_mode_traps_reads not implemented yet :( -- Yunhong xen-devel-bounces@xxxxxxxxxxxxxxxxxxx <> wrote: > Thanks for your explaination. > I notice some anti-virus application clear CR0.WP, so maybe we need to > consider this support. > > -- Yunhong > > xen-devel-bounces@xxxxxxxxxxxxxxxxxxx <> wrote: >> It's necessary because we need to trap guest writes to pagetables, >> regardless of setting of guest CR0.WP. If it turns out we need >> to properly >> emulate CR0.WP then we'll need to come up with a scheme that does not >> require us to run the guest with real CR0.WP set. Possibly it >> will require >> us to emulate certain memory accesses. >> >> -- Keir >> >> On 8/11/07 14:23, "Jiang, Yunhong" <yunhong.jiang@xxxxxxxxx> wrote: >> >>> In "arch/x86/hvm/vmx/vmx.c", vmx_update_guest_cr(), the CR0.WP is always >>> set as following code: v->arch.hvm_vcpu.hw_cr[0] = >>> v->arch.hvm_vcpu.guest_cr[0] | >>> X86_CR0_PE | X86_CR0_NE | X86_CR0_PG | X86_CR0_WP; >>> >>> I'm wondering are there any special reason for this? I try to check >>> shadow code and didn't find any clue. >>> Can anyone give me some hints? >>> >>> Thanks >>> Yunhong Jiang >>> >>> _______________________________________________ >>> Xen-devel mailing list >>> Xen-devel@xxxxxxxxxxxxxxxxxxx >>> http://lists.xensource.com/xen-devel >> >> >> >> _______________________________________________ >> Xen-devel mailing list >> Xen-devel@xxxxxxxxxxxxxxxxxxx >> http://lists.xensource.com/xen-devel > > _______________________________________________ > Xen-devel mailing list > Xen-devel@xxxxxxxxxxxxxxxxxxx > http://lists.xensource.com/xen-devel _______________________________________________ Xen-devel mailing list Xen-devel@xxxxxxxxxxxxxxxxxxx http://lists.xensource.com/xen-devel
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