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| author | Ed Swierk <eswierk@aristanetworks.com> | 2009-10-16 02:21:43 +0400 |
|---|---|---|
| committer | Avi Kivity <avi@redhat.com> | 2009-12-03 10:32:18 +0300 |
| commit | ffde22ac53b6d6b1d7206f1172176a667eead778 (patch) | |
| tree | 16ab77d364ba26928136e6d18463845941b6dd2c /arch/x86/include/asm/kvm.h | |
| parent | 94c30d9ca6fd00a69e367b91b6e13572c41938c5 (diff) | |
| download | linux-ffde22ac53b6d6b1d7206f1172176a667eead778.tar.xz | |
KVM: Xen PV-on-HVM guest support
Support for Xen PV-on-HVM guests can be implemented almost entirely in
userspace, except for handling one annoying MSR that maps a Xen
hypercall blob into guest address space.
A generic mechanism to delegate MSR writes to userspace seems overkill
and risks encouraging similar MSR abuse in the future. Thus this patch
adds special support for the Xen HVM MSR.
I implemented a new ioctl, KVM_XEN_HVM_CONFIG, that lets userspace tell
KVM which MSR the guest will write to, as well as the starting address
and size of the hypercall blobs (one each for 32-bit and 64-bit) that
userspace has loaded from files. When the guest writes to the MSR, KVM
copies one page of the blob from userspace to the guest.
I've tested this patch with a hacked-up version of Gerd's userspace
code, booting a number of guests (CentOS 5.3 i386 and x86_64, and
FreeBSD 8.0-RC1 amd64) and exercising PV network and block devices.
[jan: fix i386 build warning]
[avi: future proof abi with a flags field]
Signed-off-by: Ed Swierk <eswierk@aristanetworks.com>
Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
Diffstat (limited to 'arch/x86/include/asm/kvm.h')
| -rw-r--r-- | arch/x86/include/asm/kvm.h | 1 |
1 files changed, 1 insertions, 0 deletions
diff --git a/arch/x86/include/asm/kvm.h b/arch/x86/include/asm/kvm.h index f02e87a5206f..ef9b4b73cce4 100644 --- a/arch/x86/include/asm/kvm.h +++ b/arch/x86/include/asm/kvm.h @@ -19,6 +19,7 @@ #define __KVM_HAVE_MSIX #define __KVM_HAVE_MCE #define __KVM_HAVE_PIT_STATE2 +#define __KVM_HAVE_XEN_HVM /* Architectural interrupt line count. */ #define KVM_NR_INTERRUPTS 256 |