Commit 2d5ba19b authored by Marcelo Tosatti's avatar Marcelo Tosatti Committed by Paolo Bonzini
Browse files

kvm: x86: add host poll control msrs 



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: default avatarMarcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: default avatarPaolo Bonzini <pbonzini@redhat.com>
parent fdb28619

Documentation/virtual/kvm/msr.txt

+9 −0
Original line number Diff line number Diff line
@@ -273,3 +273,12 @@ MSR_KVM_EOI_EN: 0x4b564d04 
	guest must both read the least significant bit in the memory area and

	clear it using a single CPU instruction, such as test and clear, or

	compare and exchange.



MSR_KVM_POLL_CONTROL: 0x4b564d05

	Control host-side polling.



	data: Bit 0 enables (1) or disables (0) host-side HLT polling logic.



	KVM guests can request the host not to poll on HLT, for example if

	they are performing polling themselves.

arch/x86/include/asm/kvm_host.h

+2 −0
Original line number Diff line number Diff line
@@ -755,6 +755,8 @@ struct kvm_vcpu_arch { 
		struct gfn_to_hva_cache data;

	} pv_eoi;



	u64 msr_kvm_poll_control;



	/*

	 * Indicate whether the access faults on its page table in guest

	 * which is set when fix page fault and used to detect unhandeable

arch/x86/include/uapi/asm/kvm_para.h

+2 −0
Original line number Diff line number Diff line
@@ -29,6 +29,7 @@ 
#define KVM_FEATURE_PV_TLB_FLUSH	9

#define KVM_FEATURE_ASYNC_PF_VMEXIT	10

#define KVM_FEATURE_PV_SEND_IPI	11

#define KVM_FEATURE_POLL_CONTROL	12



#define KVM_HINTS_REALTIME      0
@@ -47,6 +48,7 @@ 
#define MSR_KVM_ASYNC_PF_EN 0x4b564d02

#define MSR_KVM_STEAL_TIME  0x4b564d03

#define MSR_KVM_PV_EOI_EN      0x4b564d04

#define MSR_KVM_POLL_CONTROL	0x4b564d05



struct kvm_steal_time {

	__u64 steal;

arch/x86/kvm/Kconfig

+1 −0
Original line number Diff line number Diff line
@@ -41,6 +41,7 @@ config KVM 
	select PERF_EVENTS

	select HAVE_KVM_MSI

	select HAVE_KVM_CPU_RELAX_INTERCEPT

	select HAVE_KVM_NO_POLL

	select KVM_GENERIC_DIRTYLOG_READ_PROTECT

	select KVM_VFIO

	select SRCU

arch/x86/kvm/cpuid.c

+2 −1
Original line number Diff line number Diff line
@@ -658,7 +658,8 @@ static inline int __do_cpuid_ent(struct kvm_cpuid_entry2 *entry, u32 function, 
			     (1 << KVM_FEATURE_PV_UNHALT) |

			     (1 << KVM_FEATURE_PV_TLB_FLUSH) |

			     (1 << KVM_FEATURE_ASYNC_PF_VMEXIT) |

			     (1 << KVM_FEATURE_PV_SEND_IPI);

			     (1 << KVM_FEATURE_PV_SEND_IPI) |

			     (1 << KVM_FEATURE_POLL_CONTROL);



		if (sched_info_on())

			entry->eax |= (1 << KVM_FEATURE_STEAL_TIME);