[PATCH] KVM: svm: remove KVM_QUIRK_CD_NW_CLEARED quirk

2015-07-10 Thread Paolo Bonzini
We can disable CD unconditionally when there is no assigned device. KVM now forces guest PAT to all-writeback in that case, so it makes sense to also force CR0.CD=0. When there are assigned devices, emulate cache-disabled operation through the page tables. This behavior is consistent with VMX,

Re: [PATCH] KVM: svm: remove KVM_QUIRK_CD_NW_CLEARED quirk

2015-07-10 Thread Joerg Roedel
On Fri, Jul 10, 2015 at 02:01:33PM +0200, Paolo Bonzini wrote: We can disable CD unconditionally when there is no assigned device. KVM now forces guest PAT to all-writeback in that case, so it makes sense to also force CR0.CD=0. When there are assigned devices, emulate cache-disabled

Re: [PATCH] KVM: svm: remove KVM_QUIRK_CD_NW_CLEARED quirk

2015-07-10 Thread Xiao Guangrong
On 07/10/2015 08:01 PM, Paolo Bonzini wrote: We can disable CD unconditionally when there is no assigned device. KVM now forces guest PAT to all-writeback in that case, so it makes sense to also force CR0.CD=0. When there are assigned devices, emulate cache-disabled operation through the page