| Message ID | 1309793548-16714-4-git-send-email-glommer@redhat.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On Mon, 04 Jul 2011, Glauber Costa wrote: > To implement steal time, we need the hypervisor to pass the guest information > about how much time was spent running other processes outside the VM. > This is per-vcpu, and using the kvmclock structure for that is an abuse > we decided not to make. > > In this patchset, I am introducing a new msr, KVM_MSR_STEAL_TIME, that > holds the memory area address containing information about steal time > > This patch contains the headers for it. I am keeping it separate to facilitate > backports to people who wants to backport the kernel part but not the > hypervisor, or the other way around. > > Signed-off-by: Glauber Costa <glommer@redhat.com> > CC: Rik van Riel <riel@redhat.com> > CC: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com> > CC: Peter Zijlstra <peterz@infradead.org> > CC: Avi Kivity <avi@redhat.com> > CC: Anthony Liguori <aliguori@us.ibm.com> > CC: Eric B Munson <emunson@mgebm.net> Tested-by: Eric B Munson <emunson@mgebm.net>
On 07/04/2011 11:32 AM, Glauber Costa wrote: > To implement steal time, we need the hypervisor to pass the guest information > about how much time was spent running other processes outside the VM. > This is per-vcpu, and using the kvmclock structure for that is an abuse > we decided not to make. > > In this patchset, I am introducing a new msr, KVM_MSR_STEAL_TIME, that > holds the memory area address containing information about steal time > > This patch contains the headers for it. I am keeping it separate to facilitate > backports to people who wants to backport the kernel part but not the > hypervisor, or the other way around. > > Signed-off-by: Glauber Costa<glommer@redhat.com> > CC: Rik van Riel<riel@redhat.com> > CC: Jeremy Fitzhardinge<jeremy.fitzhardinge@citrix.com> > CC: Peter Zijlstra<peterz@infradead.org> > CC: Avi Kivity<avi@redhat.com> > CC: Anthony Liguori<aliguori@us.ibm.com> > CC: Eric B Munson<emunson@mgebm.net> Acked-by: Rik van Riel <riel@redhat.com>
diff --git a/Documentation/virtual/kvm/msr.txt b/Documentation/virtual/kvm/msr.txt index d079aed..38db3f8 100644 --- a/Documentation/virtual/kvm/msr.txt +++ b/Documentation/virtual/kvm/msr.txt @@ -185,3 +185,38 @@ MSR_KVM_ASYNC_PF_EN: 0x4b564d02 Currently type 2 APF will be always delivered on the same vcpu as type 1 was, but guest should not rely on that. + +MSR_KVM_STEAL_TIME: 0x4b564d03 + + data: 64-byte alignment physical address of a memory area which must be + in guest RAM, plus an enable bit in bit 0. This memory is expected to + hold a copy of the following structure: + + struct kvm_steal_time { + __u64 steal; + __u32 version; + __u32 flags; + __u32 pad[12]; + } + + whose data will be filled in by the hypervisor periodically. Only one + write, or registration, is needed for each VCPU. The interval between + updates of this structure is arbitrary and implementation-dependent. + The hypervisor may update this structure at any time it sees fit until + anything with bit0 == 0 is written to it. Guest is required to make sure + this structure is initialized to zero. + + Fields have the following meanings: + + version: a sequence counter. In other words, guest has to check + this field before and after grabbing time information and make + sure they are both equal and even. An odd version indicates an + in-progress update. + + flags: At this point, always zero. May be used to indicate + changes in this structure in the future. + + steal: the amount of time in which this vCPU did not run, in + nanoseconds. Time during which the vcpu is idle, will not be + reported as steal time. + diff --git a/arch/x86/include/asm/kvm_para.h b/arch/x86/include/asm/kvm_para.h index d6cd79b..65f8bb9 100644 --- a/arch/x86/include/asm/kvm_para.h +++ b/arch/x86/include/asm/kvm_para.h @@ -21,6 +21,7 @@ */ #define KVM_FEATURE_CLOCKSOURCE2 3 #define KVM_FEATURE_ASYNC_PF 4 +#define KVM_FEATURE_STEAL_TIME 5 /* The last 8 bits are used to indicate how to interpret the flags field * in pvclock structure. If no bits are set, all flags are ignored. @@ -35,6 +36,14 @@ #define MSR_KVM_WALL_CLOCK_NEW 0x4b564d00 #define MSR_KVM_SYSTEM_TIME_NEW 0x4b564d01 #define MSR_KVM_ASYNC_PF_EN 0x4b564d02 +#define MSR_KVM_STEAL_TIME 0x4b564d03 + +struct kvm_steal_time { + __u64 steal; + __u32 version; + __u32 flags; + __u32 pad[12]; +}; #define KVM_MAX_MMU_OP_BATCH 32
To implement steal time, we need the hypervisor to pass the guest information about how much time was spent running other processes outside the VM. This is per-vcpu, and using the kvmclock structure for that is an abuse we decided not to make. In this patchset, I am introducing a new msr, KVM_MSR_STEAL_TIME, that holds the memory area address containing information about steal time This patch contains the headers for it. I am keeping it separate to facilitate backports to people who wants to backport the kernel part but not the hypervisor, or the other way around. Signed-off-by: Glauber Costa <glommer@redhat.com> CC: Rik van Riel <riel@redhat.com> CC: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com> CC: Peter Zijlstra <peterz@infradead.org> CC: Avi Kivity <avi@redhat.com> CC: Anthony Liguori <aliguori@us.ibm.com> CC: Eric B Munson <emunson@mgebm.net> --- Documentation/virtual/kvm/msr.txt | 35 +++++++++++++++++++++++++++++++++++ arch/x86/include/asm/kvm_para.h | 9 +++++++++ 2 files changed, 44 insertions(+), 0 deletions(-)