From: Marcelo Tosatti <mtosatti@redhat.com>
To: kvm-devel <kvm@vger.kernel.org>
Cc: Paolo Bonzini <pbonzini@redhat.com>,
Radim Krcmar <rkrcmar@redhat.com>,
Andrea Arcangeli <aarcange@redhat.com>,
"Rafael J. Wysocki" <rafael.j.wysocki@intel.com>,
Peter Zijlstra <peterz@infradead.org>,
Wanpeng Li <kernellwp@gmail.com>,
Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>,
Raslan KarimAllah <karahmed@amazon.de>,
Boris Ostrovsky <boris.ostrovsky@oracle.com>,
Ankur Arora <ankur.a.arora@oracle.com>,
Christian Borntraeger <borntraeger@de.ibm.com>,
linux-pm@vger.kernel.org, Marcelo Tosatti <mtosatti@redhat.com>
Subject: [patch 4/5] kvm: x86: add host poll control msrs
Date: Thu, 13 Jun 2019 18:45:36 -0400 [thread overview]
Message-ID: <20190613225023.067845318@redhat.com> (raw)
In-Reply-To: 20190613224532.949768676@redhat.com
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>
---
Documentation/virtual/kvm/msr.txt | 9 +++++++++
arch/x86/include/asm/kvm_host.h | 2 ++
arch/x86/include/uapi/asm/kvm_para.h | 2 ++
arch/x86/kvm/Kconfig | 1 +
arch/x86/kvm/cpuid.c | 3 ++-
arch/x86/kvm/x86.c | 23 +++++++++++++++++++++++
6 files changed, 39 insertions(+), 1 deletion(-)
Index: linux-2.6.git/Documentation/virtual/kvm/msr.txt
===================================================================
--- linux-2.6.git.orig/Documentation/virtual/kvm/msr.txt 2019-06-13 18:41:40.127920237 -0400
+++ linux-2.6.git/Documentation/virtual/kvm/msr.txt 2019-06-13 18:42:06.149503132 -0400
@@ -273,3 +273,12 @@
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 halt poll
+ logic.
+ KVM guests can disable host halt polling when performing
+ polling themselves.
+
Index: linux-2.6.git/arch/x86/include/asm/kvm_host.h
===================================================================
--- linux-2.6.git.orig/arch/x86/include/asm/kvm_host.h 2019-06-13 18:41:40.127920237 -0400
+++ linux-2.6.git/arch/x86/include/asm/kvm_host.h 2019-06-13 18:42:06.149503132 -0400
@@ -755,6 +755,8 @@
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
Index: linux-2.6.git/arch/x86/include/uapi/asm/kvm_para.h
===================================================================
--- linux-2.6.git.orig/arch/x86/include/uapi/asm/kvm_para.h 2019-06-13 18:41:40.127920237 -0400
+++ linux-2.6.git/arch/x86/include/uapi/asm/kvm_para.h 2019-06-13 18:42:06.150503116 -0400
@@ -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;
Index: linux-2.6.git/arch/x86/kvm/Kconfig
===================================================================
--- linux-2.6.git.orig/arch/x86/kvm/Kconfig 2019-06-13 18:41:40.127920237 -0400
+++ linux-2.6.git/arch/x86/kvm/Kconfig 2019-06-13 18:42:06.150503116 -0400
@@ -41,6 +41,7 @@
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
Index: linux-2.6.git/arch/x86/kvm/cpuid.c
===================================================================
--- linux-2.6.git.orig/arch/x86/kvm/cpuid.c 2019-06-13 18:41:40.127920237 -0400
+++ linux-2.6.git/arch/x86/kvm/cpuid.c 2019-06-13 18:42:06.150503116 -0400
@@ -643,7 +643,8 @@
(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);
Index: linux-2.6.git/arch/x86/kvm/x86.c
===================================================================
--- linux-2.6.git.orig/arch/x86/kvm/x86.c 2019-06-13 18:41:40.127920237 -0400
+++ linux-2.6.git/arch/x86/kvm/x86.c 2019-06-13 18:42:06.151503100 -0400
@@ -1177,6 +1177,7 @@
MSR_IA32_POWER_CTL,
MSR_K7_HWCR,
+ MSR_KVM_POLL_CONTROL,
};
static unsigned num_emulated_msrs;
@@ -2628,6 +2629,14 @@
return 1;
break;
+ case MSR_KVM_POLL_CONTROL:
+ /* only enable bit supported */
+ if (data & (-1ULL << 1))
+ return 1;
+
+ vcpu->arch.msr_kvm_poll_control = data;
+ break;
+
case MSR_IA32_MCG_CTL:
case MSR_IA32_MCG_STATUS:
case MSR_IA32_MC0_CTL ... MSR_IA32_MCx_CTL(KVM_MAX_MCE_BANKS) - 1:
@@ -2877,6 +2886,9 @@
case MSR_KVM_PV_EOI_EN:
msr_info->data = vcpu->arch.pv_eoi.msr_val;
break;
+ case MSR_KVM_POLL_CONTROL:
+ msr_info->data = vcpu->arch.msr_kvm_poll_control;
+ break;
case MSR_IA32_P5_MC_ADDR:
case MSR_IA32_P5_MC_TYPE:
case MSR_IA32_MCG_CAP:
@@ -8877,6 +8889,10 @@
msr.host_initiated = true;
kvm_write_tsc(vcpu, &msr);
vcpu_put(vcpu);
+
+ /* poll control enabled by default */
+ vcpu->arch.msr_kvm_poll_control = 1;
+
mutex_unlock(&vcpu->mutex);
if (!kvmclock_periodic_sync)
@@ -9951,6 +9967,13 @@
}
EXPORT_SYMBOL_GPL(kvm_vector_hashing_enabled);
+bool kvm_arch_no_poll(struct kvm_vcpu *vcpu)
+{
+ return (vcpu->arch.msr_kvm_poll_control & 1) == 0;
+}
+EXPORT_SYMBOL_GPL(kvm_arch_no_poll);
+
+
EXPORT_TRACEPOINT_SYMBOL_GPL(kvm_exit);
EXPORT_TRACEPOINT_SYMBOL_GPL(kvm_fast_mmio);
EXPORT_TRACEPOINT_SYMBOL_GPL(kvm_inj_virq);
next prev parent reply other threads:[~2019-06-13 22:55 UTC|newest]
Thread overview: 13+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-06-13 22:45 [patch 0/5] cpuidle haltpoll driver and governor (v4) Marcelo Tosatti
2019-06-13 22:45 ` [patch 1/5] drivers/cpuidle: add cpuidle-haltpoll driver Marcelo Tosatti
2019-06-25 21:50 ` Rafael J. Wysocki
2019-06-26 8:40 ` Rafael J. Wysocki
2019-06-13 22:45 ` [patch 2/5] cpuidle: add get_poll_time callback Marcelo Tosatti
2019-06-25 21:52 ` Rafael J. Wysocki
2019-06-13 22:45 ` [patch 3/5] cpuidle: add haltpoll governor Marcelo Tosatti
2019-06-21 0:34 ` Doug Smythies
2019-06-27 18:08 ` Marcelo Tosatti
2019-06-25 21:57 ` Rafael J. Wysocki
2019-06-13 22:45 ` Marcelo Tosatti [this message]
2019-06-13 22:45 ` [patch 5/5] cpuidle-haltpoll: disable host side polling when kvm virtualized Marcelo Tosatti
2019-07-01 18:53 [patch 0/5] cpuidle haltpoll driver and governor (v5) Marcelo Tosatti
2019-07-01 18:53 ` [patch 4/5] kvm: x86: add host poll control msrs Marcelo Tosatti
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