David Woodhouse d8ba8ba4c8 KVM: x86/xen: Allow XEN_RUNSTATE_UPDATE flag behaviour to be configured ... Closer inspection of the Xen code shows that we aren't supposed to be using the XEN_RUNSTATE_UPDATE flag unconditionally. It should be explicitly enabled by guests through the HYPERVISOR_vm_assist hypercall. If we randomly set the top bit of ->state_entry_time for a guest that hasn't asked for it and doesn't expect it, that could make the runtimes fail to add up and confuse the guest. Without the flag it's perfectly safe for a vCPU to read its own vcpu_runstate_info; just not for one vCPU to read *another's*. I briefly pondered adding a word for the whole set of VMASST_TYPE_* flags but the only one we care about for HVM guests is this, so it seemed a bit pointless. Signed-off-by: David Woodhouse <dwmw@amazon.co.uk> Message-Id: <20221127122210.248427-3-dwmw2@infradead.org> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>		2022-11-30 10:59:37 -05:00
..
asm	KVM: x86/xen: Allow XEN_RUNSTATE_UPDATE flag behaviour to be configured	2022-11-30 10:59:37 -05:00
uapi/asm	KVM: x86: Add a VALID_MASK for the flags in kvm_msr_filter_range	2022-11-09 12:31:30 -05:00