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authorAshish Kalra <ashish.kalra@amd.com>2021-06-08 18:05:43 +0000
committerPaolo Bonzini <pbonzini@redhat.com>2021-06-17 14:25:39 -0400
commit0dbb11230437895f7cd6fc55da61cef011e997d8 (patch)
treee545b953c952a6becff1d20bc6225c0d91db0be1 /Documentation/virt/kvm/msr.rst
parentKVM: switch per-VM stats to u64 (diff)
downloadwireguard-linux-0dbb11230437895f7cd6fc55da61cef011e997d8.tar.xz
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KVM: X86: Introduce KVM_HC_MAP_GPA_RANGE hypercall
This hypercall is used by the SEV guest to notify a change in the page encryption status to the hypervisor. The hypercall should be invoked only when the encryption attribute is changed from encrypted -> decrypted and vice versa. By default all guest pages are considered encrypted. The hypercall exits to userspace to manage the guest shared regions and integrate with the userspace VMM's migration code. Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Ingo Molnar <mingo@redhat.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Joerg Roedel <joro@8bytes.org> Cc: Borislav Petkov <bp@suse.de> Cc: Tom Lendacky <thomas.lendacky@amd.com> Cc: x86@kernel.org Cc: kvm@vger.kernel.org Cc: linux-kernel@vger.kernel.org Reviewed-by: Steve Rutherford <srutherford@google.com> Signed-off-by: Brijesh Singh <brijesh.singh@amd.com> Signed-off-by: Ashish Kalra <ashish.kalra@amd.com> Co-developed-by: Sean Christopherson <seanjc@google.com> Signed-off-by: Sean Christopherson <seanjc@google.com> Co-developed-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Message-Id: <90778988e1ee01926ff9cac447aacb745f954c8c.1623174621.git.ashish.kalra@amd.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Diffstat (limited to 'Documentation/virt/kvm/msr.rst')
-rw-r--r--Documentation/virt/kvm/msr.rst13
1 files changed, 13 insertions, 0 deletions
diff --git a/Documentation/virt/kvm/msr.rst b/Documentation/virt/kvm/msr.rst
index e37a14c323d2..9315fc385fb0 100644
--- a/Documentation/virt/kvm/msr.rst
+++ b/Documentation/virt/kvm/msr.rst
@@ -376,3 +376,16 @@ data:
write '1' to bit 0 of the MSR, this causes the host to re-scan its queue
and check if there are more notifications pending. The MSR is available
if KVM_FEATURE_ASYNC_PF_INT is present in CPUID.
+
+MSR_KVM_MIGRATION_CONTROL:
+ 0x4b564d08
+
+data:
+ This MSR is available if KVM_FEATURE_MIGRATION_CONTROL is present in
+ CPUID. Bit 0 represents whether live migration of the guest is allowed.
+
+ When a guest is started, bit 0 will be 0 if the guest has encrypted
+ memory and 1 if the guest does not have encrypted memory. If the
+ guest is communicating page encryption status to the host using the
+ ``KVM_HC_MAP_GPA_RANGE`` hypercall, it can set bit 0 in this MSR to
+ allow live migration of the guest.