Liran Alon 6c6a2ab962 KVM: VMX: Nop emulation of MSR_IA32_POWER_CTL ... Since commits 668fffa3f8 ("kvm: better MWAIT emulation for guestsâ€) and 4d5422cea3 ("KVM: X86: Provide a capability to disable MWAIT interceptsâ€), KVM was modified to allow an admin to configure certain guests to execute MONITOR/MWAIT inside guest without being intercepted by host. This is useful in case admin wishes to allocate a dedicated logical processor for each vCPU thread. Thus, making it safe for guest to completely control the power-state of the logical processor. The ability to use this new KVM capability was introduced to QEMU by commits 6f131f13e68d ("kvm: support -overcommit cpu-pm=on|offâ€) and 2266d4431132 ("i386/cpu: make -cpu host support monitor/mwaitâ€). However, exposing MONITOR/MWAIT to a Linux guest may cause it's intel_idle kernel module to execute c1e_promotion_disable() which will attempt to RDMSR/WRMSR from/to MSR_IA32_POWER_CTL to manipulate the "C1E Enable" bit. This behaviour was introduced by commit 32e9518005 ("intel_idle: export both C1 and C1Eâ€). Becuase KVM doesn't emulate this MSR, running KVM with ignore_msrs=0 will cause the above guest behaviour to raise a #GP which will cause guest to kernel panic. Therefore, add support for nop emulation of MSR_IA32_POWER_CTL to avoid #GP in guest in this scenario. Future commits can optimise emulation further by reflecting guest MSR changes to host MSR to provide guest with the ability to fine-tune the dedicated logical processor power-state. Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com> Signed-off-by: Liran Alon <liran.alon@oracle.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>		2019-04-30 21:32:14 +02:00
..
capabilities.h
evmcs.c	x86/kvm/hyper-v: nested_enable_evmcs() sets vmcs_version incorrectly	2019-01-25 19:11:37 +01:00
evmcs.h
nested.c	KVM: nVMX: Return -EINVAL when signaling failure in VM-Entry helpers	2019-04-16 15:39:06 +02:00
nested.h
ops.h
pmu_intel.c	KVM: x86: Add support of clear Trace_ToPA_PMI status	2019-04-30 21:32:14 +02:00
vmcs12.c
vmcs12.h
vmcs_shadow_fields.h
vmcs.h	KVM: nVMX: Cache host_rsp on a per-VMCS basis	2019-02-12 13:12:22 +01:00
vmenter.S	KVM: VMX: Reorder clearing of registers in the vCPU-run assembly flow	2019-02-20 22:48:18 +01:00
vmx.c	KVM: VMX: Nop emulation of MSR_IA32_POWER_CTL	2019-04-30 21:32:14 +02:00
vmx.h	KVM: VMX: Nop emulation of MSR_IA32_POWER_CTL	2019-04-30 21:32:14 +02:00