From: Paul Durrant <pdurrant@xxxxxxxxxx>
The following text from the original cover letter still serves as an
introduction to the series:
"Currently we treat the shared_info page as guest memory and the VMM
informs KVM of its location using a GFN. However it is not guest memory as
such; it's an overlay page. So we pointlessly invalidate and re-cache a
mapping to the *same page* of memory every time the guest requests that
shared_info be mapped into its address space. Let's avoid doing that by
modifying the pfncache code to allow activation using a fixed userspace HVA
as well as a GPA."
As with the previous version of the series, both the shared_info and
vcpu_info caches can now be activated using an HVA but the commit comment
on "map shared_info using HVA rather than GFN" has been extended to
explain why mapping shared_info using HVA is a particularly good idea.
This version of the series also includes an extra patch to "allow
vcpu_info content to be 'safely' copied. Currently there is a race window
when the VMM performs the copy; this patch allows the VMM to avoid that
race.
Paul Durrant (11):
KVM: pfncache: add a map helper function
KVM: pfncache: add a mark-dirty helper
KVM: pfncache: add a helper to get the gpa
KVM: pfncache: base offset check on khva rather than gpa
KVM: pfncache: allow a cache to be activated with a fixed (userspace)
HVA
KVM: xen: allow shared_info to be mapped by fixed HVA
KVM: xen: allow vcpu_info to be mapped by fixed HVA
KVM: selftests / xen: map shared_info using HVA rather than GFN
KVM: selftests / xen: re-map vcpu_info using HVA rather than GPA
KVM: xen: advertize the KVM_XEN_HVM_CONFIG_SHARED_INFO_HVA capability
KVM: xen: allow vcpu_info content to be 'safely' copied
Documentation/virt/kvm/api.rst | 53 +++++--
arch/x86/kvm/x86.c | 5 +-
arch/x86/kvm/xen.c | 92 +++++++++----
include/linux/kvm_host.h | 43 ++++++
include/linux/kvm_types.h | 3 +-
include/uapi/linux/kvm.h | 9 +-
.../selftests/kvm/x86_64/xen_shinfo_test.c | 59 ++++++--
virt/kvm/pfncache.c | 129 +++++++++++++-----
8 files changed, 302 insertions(+), 91 deletions(-)
--
2.39.2
