diff options
| author | Ed Swierk | 2009-10-15 15:21:43 -0700 |
|---|---|---|
| committer | Avi Kivity | 2009-12-03 09:32:18 +0200 |
| commit | ffde22ac53b6d6b1d7206f1172176a667eead778 (patch) | |
| tree | 16ab77d364ba26928136e6d18463845941b6dd2c /arch/x86/include | |
| parent | 94c30d9ca6fd00a69e367b91b6e13572c41938c5 (diff) | |
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')
| -rw-r--r-- | arch/x86/include/asm/kvm.h | 1 | ||||
| -rw-r--r-- | arch/x86/include/asm/kvm_host.h | 2 |
2 files changed, 3 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 diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h index 179a919f53a4..36f3b53f5c27 100644 --- a/arch/x86/include/asm/kvm_host.h +++ b/arch/x86/include/asm/kvm_host.h @@ -410,6 +410,8 @@ struct kvm_arch{ unsigned long irq_sources_bitmap; u64 vm_init_tsc; + + struct kvm_xen_hvm_config xen_hvm_config; }; struct kvm_vm_stat { |