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| author | Ed Swierk <eswierk@aristanetworks.com> | 2009-10-15 15:21:43 -0700 |
|---|---|---|
| committer | Avi Kivity <avi@redhat.com> | 2009-12-03 09:32:18 +0200 |
| commit | ffde22ac53b6d6b1d7206f1172176a667eead778 (patch) | |
| tree | 16ab77d364ba26928136e6d18463845941b6dd2c /include | |
| parent | 94c30d9ca6fd00a69e367b91b6e13572c41938c5 (diff) | |
| download | op-kernel-dev-ffde22ac53b6d6b1d7206f1172176a667eead778.zip op-kernel-dev-ffde22ac53b6d6b1d7206f1172176a667eead778.tar.gz | |
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 'include')
| -rw-r--r-- | include/linux/kvm.h | 16 |
1 files changed, 16 insertions, 0 deletions
diff --git a/include/linux/kvm.h b/include/linux/kvm.h index f8f8900..b694c1d 100644 --- a/include/linux/kvm.h +++ b/include/linux/kvm.h @@ -436,6 +436,9 @@ struct kvm_ioeventfd { #endif #define KVM_CAP_IOEVENTFD 36 #define KVM_CAP_SET_IDENTITY_MAP_ADDR 37 +#ifdef __KVM_HAVE_XEN_HVM +#define KVM_CAP_XEN_HVM 38 +#endif #ifdef KVM_CAP_IRQ_ROUTING @@ -488,6 +491,18 @@ struct kvm_x86_mce { }; #endif +#ifdef KVM_CAP_XEN_HVM +struct kvm_xen_hvm_config { + __u32 flags; + __u32 msr; + __u64 blob_addr_32; + __u64 blob_addr_64; + __u8 blob_size_32; + __u8 blob_size_64; + __u8 pad2[30]; +}; +#endif + #define KVM_IRQFD_FLAG_DEASSIGN (1 << 0) struct kvm_irqfd { @@ -546,6 +561,7 @@ struct kvm_irqfd { #define KVM_CREATE_PIT2 _IOW(KVMIO, 0x77, struct kvm_pit_config) #define KVM_SET_BOOT_CPU_ID _IO(KVMIO, 0x78) #define KVM_IOEVENTFD _IOW(KVMIO, 0x79, struct kvm_ioeventfd) +#define KVM_XEN_HVM_CONFIG _IOW(KVMIO, 0x7a, struct kvm_xen_hvm_config) /* * ioctls for vcpu fds |
