On 06/06/2017 05:35 PM, Andy Lutomirski wrote: > On Tue, Jun 6, 2017 at 2:31 PM, Boris Ostrovsky > <boris.ostrovsky@xxxxxxxxxx> wrote: >>> --- a/arch/x86/xen/setup.c >>> +++ b/arch/x86/xen/setup.c >>> @@ -1037,6 +1037,12 @@ void __init xen_arch_setup(void) >>> } >>> #endif >>> >>> + /* >>> + * Xen would need some work to support PCID: CR3 handling as well >>> + * as xen_flush_tlb_others() would need updating. >>> + */ >>> + setup_clear_cpu_cap(X86_FEATURE_PCID); >> >> Capabilities for PV guests are typically set in xen_init_capabilities() now. > Do I need this just for PV or for all Xen guests? Do the > hardware-assisted guests still use paravirt flushes? Does the > hypervisor either support PCID or correctly clear the PCID CPUID bit? For HVM guests Xen will DTRT for CPUID so dealing with PV should be sufficient (and xen_arch_setup() is called on PV only anyway) As far as flushes are concerned for now it's PV only although I believe Juergen is thinking about doing this on HVM too. -boris -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>
