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2019-07-24Documentation: move Documentation/virtual to Documentation/virtChristoph Hellwig1-284/+0
Renaming docs seems to be en vogue at the moment, so fix on of the grossly misnamed directories. We usually never use "virtual" as a shortcut for virtualization in the kernel, but always virt, as seen in the virt/ top-level directory. Fix up the documentation to match that. Fixes: ed16648eb5b8 ("Move kvm, uml, and lguest subdirectories under a common "virtual" directory, I.E:") Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2019-06-18kvm: x86: add host poll control msrsMarcelo Tosatti1-0/+9
Add an MSRs which allows the guest to disable host polling (specifically the cpuidle-haltpoll, when performing polling in the guest, disables host side polling). Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2018-02-24KVM: x86: fix backward migration with async_PFRadim Krčmář1-1/+2
Guests on new hypersiors might set KVM_ASYNC_PF_DELIVERY_AS_PF_VMEXIT bit when enabling async_PF, but this bit is reserved on old hypervisors, which results in a failure upon migration. To avoid breaking different cases, we are checking for CPUID feature bit before enabling the feature and nothing else. Fixes: 52a5c155cf79 ("KVM: async_pf: Let guest support delivery of async_pf from guest mode") Cc: <stable@vger.kernel.org> Reviewed-by: Wanpeng Li <wanpengli@tencent.com> Reviewed-by: David Hildenbrand <david@redhat.com> Signed-off-by: Radim Krčmář <rkrcmar@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2017-07-14KVM: async_pf: Let guest support delivery of async_pf from guest modeWanpeng Li1-2/+3
Adds another flag bit (bit 2) to MSR_KVM_ASYNC_PF_EN. If bit 2 is 1, async page faults are delivered to L1 as #PF vmexits; if bit 2 is 0, kvm_can_do_async_pf returns 0 if in guest mode. This is similar to what svm.c wanted to do all along, but it is only enabled for Linux as L1 hypervisor. Foreign hypervisors must never receive async page faults as vmexits, because they'd probably be very confused about that. Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Radim Krčmář <rkrcmar@redhat.com> Signed-off-by: Wanpeng Li <wanpeng.li@hotmail.com> Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
2016-11-22Documentation/virtual/kvm: Support the vCPU preemption checkPan Xinhui1-1/+8
Commit ("x86/kvm: support vCPU preemption check") added a new struct kvm_steal_time::preempted field. This field tells us if a vCPU is running or not. It is zero if some old KVM does not support this field or if the vCPU is not preempted. Other values means the vCPU has been preempted. Signed-off-by: Pan Xinhui <xinhui.pan@linux.vnet.ibm.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Acked-by: Radim Krčmář <rkrcmar@redhat.com> Acked-by: Paolo Bonzini <pbonzini@redhat.com> Cc: David.Laight@ACULAB.COM Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: benh@kernel.crashing.org Cc: boqun.feng@gmail.com Cc: borntraeger@de.ibm.com Cc: bsingharora@gmail.com Cc: dave@stgolabs.net Cc: jgross@suse.com Cc: kernellwp@gmail.com Cc: konrad.wilk@oracle.com Cc: linuxppc-dev@lists.ozlabs.org Cc: mpe@ellerman.id.au Cc: paulmck@linux.vnet.ibm.com Cc: paulus@samba.org Cc: virtualization@lists.linux-foundation.org Cc: will.deacon@arm.com Cc: xen-devel-request@lists.xenproject.org Cc: xen-devel@lists.xenproject.org Link: http://lkml.kernel.org/r/1478077718-37424-12-git-send-email-xinhui.pan@linux.vnet.ibm.com [ Various typo fixes. ] Signed-off-by: Ingo Molnar <mingo@kernel.org>
2014-11-03Documentation: virtual: kvm: correct one bit description in APF caseTiejun Chen1-1/+1
When commit 6adba5274206 (KVM: Let host know whether the guest can handle async PF in non-userspace context.) is introduced, actually bit 2 still is reserved and should be zero. Instead, bit 1 is 1 to indicate if asynchronous page faults can be injected when vcpu is in cpl == 0, and also please see this, in the file kvm_para.h, #define KVM_ASYNC_PF_SEND_ALWAYS (1 << 1). Signed-off-by: Tiejun Chen <tiejun.chen@intel.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2012-09-17KVM: clarify kvmclock documentationStefan Fritsch1-12/+20
- mention that system time needs to be added to wallclock time - positive tsc_shift means left shift, not right - mention additional 32bit right shift Signed-off-by: Stefan Fritsch <sf@sfritsch.de> Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2012-06-25KVM: eoi msi documentationMichael S. Tsirkin1-0/+33
Document the new EOI MSR. Couldn't decide whether this change belongs conceptually on guest or host side, so a separate patch. Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: Avi Kivity <avi@redhat.com>
2012-04-08KVM: x86: Add ioctl for KVM_KVMCLOCK_CTRLEric B Munson1-0/+4
Now that we have a flag that will tell the guest it was suspended, create an interface for that communication using a KVM ioctl. Signed-off-by: Eric B Munson <emunson@mgebm.net> Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com> Signed-off-by: Avi Kivity <avi@redhat.com>
2011-07-12KVM: KVM Steal time guest/host interfaceGlauber Costa1-0/+34
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> Acked-by: Rik van Riel <riel@redhat.com> Tested-by: Eric B Munson <emunson@mgebm.net> CC: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com> CC: Peter Zijlstra <peterz@infradead.org> CC: Anthony Liguori <aliguori@us.ibm.com> Signed-off-by: Avi Kivity <avi@redhat.com>
2011-05-06Move kvm, uml, and lguest subdirectories under a common "virtual" directory, ↵Rob Landley1-0/+187
I.E: cd Documentation mkdir virtual git mv kvm uml lguest virtual Signed-off-by: Rob Landley <rlandley@parallels.com> Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>