Guests on new hypersiors might set KVM_ASYNC_PF_DELIVERY_AS_PF_VMEXIT
bit when enabling async_PF, but this bit is reserved on old hypervisors,
which results in a failure upon migration.
To avoid breaking different cases, we are checking for CPUID feature bit
before enabling the feature and nothing else.
Fixes: 52a5c155cf ("KVM: async_pf: Let guest support delivery of async_pf from guest mode")
Cc: <stable@vger.kernel.org>
Reviewed-by: Wanpeng Li <wanpengli@tencent.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Adds another flag bit (bit 2) to MSR_KVM_ASYNC_PF_EN. If bit 2 is 1,
async page faults are delivered to L1 as #PF vmexits; if bit 2 is 0,
kvm_can_do_async_pf returns 0 if in guest mode.
This is similar to what svm.c wanted to do all along, but it is only
enabled for Linux as L1 hypervisor. Foreign hypervisors must never
receive async page faults as vmexits, because they'd probably be very
confused about that.
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Radim Krčmář <rkrcmar@redhat.com>
Signed-off-by: Wanpeng Li <wanpeng.li@hotmail.com>
Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
When commit 6adba52742 (KVM: Let host know whether the guest can
handle async PF in non-userspace context.) is introduced, actually
bit 2 still is reserved and should be zero. Instead, bit 1 is 1 to
indicate if asynchronous page faults can be injected when vcpu is
in cpl == 0, and also please see this,
in the file kvm_para.h, #define KVM_ASYNC_PF_SEND_ALWAYS (1 << 1).
Signed-off-by: Tiejun Chen <tiejun.chen@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
- mention that system time needs to be added to wallclock time
- positive tsc_shift means left shift, not right
- mention additional 32bit right shift
Signed-off-by: Stefan Fritsch <sf@sfritsch.de>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Document the new EOI MSR. Couldn't decide whether this change belongs
conceptually on guest or host side, so a separate patch.
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
Now that we have a flag that will tell the guest it was suspended, create an
interface for that communication using a KVM ioctl.
Signed-off-by: Eric B Munson <emunson@mgebm.net>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
To implement steal time, we need the hypervisor to pass the guest information
about how much time was spent running other processes outside the VM.
This is per-vcpu, and using the kvmclock structure for that is an abuse
we decided not to make.
In this patchset, I am introducing a new msr, KVM_MSR_STEAL_TIME, that
holds the memory area address containing information about steal time
This patch contains the headers for it. I am keeping it separate to facilitate
backports to people who wants to backport the kernel part but not the
hypervisor, or the other way around.
Signed-off-by: Glauber Costa <glommer@redhat.com>
Acked-by: Rik van Riel <riel@redhat.com>
Tested-by: Eric B Munson <emunson@mgebm.net>
CC: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
CC: Peter Zijlstra <peterz@infradead.org>
CC: Anthony Liguori <aliguori@us.ibm.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
Radim Krčmář
Wanpeng Li
Pan Xinhui
Tiejun Chen
Stefan Fritsch
Michael S. Tsirkin
Eric B Munson
Glauber Costa
Rob Landley