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Message-Id: <20120114182553.8604.41642.sendpatchset@oc5400248562.ibm.com>
Date: Sat, 14 Jan 2012 23:55:54 +0530
From: Raghavendra K T <raghavendra.kt@...ux.vnet.ibm.com>
To: Jeremy Fitzhardinge <jeremy@...p.org>,
Randy Dunlap <rdunlap@...otime.net>, linux-doc@...r.kernel.org,
KVM <kvm@...r.kernel.org>,
Konrad Rzeszutek Wilk <konrad.wilk@...cle.com>,
Glauber Costa <glommer@...hat.com>,
Jan Kiszka <jan.kiszka@...mens.com>,
Rik van Riel <riel@...hat.com>,
Dave Jiang <dave.jiang@...el.com>,
"H. Peter Anvin" <hpa@...or.com>,
Thomas Gleixner <tglx@...utronix.de>, X86 <x86@...nel.org>,
Marcelo Tosatti <mtosatti@...hat.com>,
Gleb Natapov <gleb@...hat.com>, Avi Kivity <avi@...hat.com>,
Alexander Graf <agraf@...e.de>,
Stefano Stabellini <stefano.stabellini@...citrix.com>,
Paul Mackerras <paulus@...ba.org>,
Sedat Dilek <sedat.dilek@...il.com>,
Ingo Molnar <mingo@...hat.com>,
LKML <linux-kernel@...r.kernel.org>,
Greg Kroah-Hartman <gregkh@...e.de>,
Virtualization <virtualization@...ts.linux-foundation.org>,
Rob Landley <rlandley@...allels.com>,
Xen <xen-devel@...ts.xensource.com>
Cc: Srivatsa Vaddagiri <vatsa@...ux.vnet.ibm.com>,
Peter Zijlstra <peterz@...radead.org>,
Raghavendra K T <raghavendra.kt@...ux.vnet.ibm.com>,
Sasha Levin <levinsasha928@...il.com>,
Suzuki Poulose <suzuki@...ux.vnet.ibm.com>,
Dave Hansen <dave@...ux.vnet.ibm.com>
Subject: [PATCH RFC V4 2/5] kvm hypervisor : Add a hypercall to KVM hypervisor to support pv-ticketlocks
Add a hypercall to KVM hypervisor to support pv-ticketlocks
KVM_HC_KICK_CPU allows the calling vcpu to kick another vcpu out of halt state.
The presence of these hypercalls is indicated to guest via
KVM_FEATURE_PVLOCK_KICK/KVM_CAP_PVLOCK_KICK.
Qemu needs a corresponding patch to pass up the presence of this feature to
guest via cpuid. Patch to qemu will be sent separately.
Signed-off-by: Srivatsa Vaddagiri <vatsa@...ux.vnet.ibm.com>
Signed-off-by: Suzuki Poulose <suzuki@...ibm.com>
Signed-off-by: Raghavendra K T <raghavendra.kt@...ux.vnet.ibm.com>
---
diff --git a/arch/x86/include/asm/kvm_para.h b/arch/x86/include/asm/kvm_para.h
index 734c376..7a94987 100644
--- a/arch/x86/include/asm/kvm_para.h
+++ b/arch/x86/include/asm/kvm_para.h
@@ -16,12 +16,14 @@
#define KVM_FEATURE_CLOCKSOURCE 0
#define KVM_FEATURE_NOP_IO_DELAY 1
#define KVM_FEATURE_MMU_OP 2
+
/* This indicates that the new set of kvmclock msrs
* are available. The use of 0x11 and 0x12 is deprecated
*/
#define KVM_FEATURE_CLOCKSOURCE2 3
#define KVM_FEATURE_ASYNC_PF 4
#define KVM_FEATURE_STEAL_TIME 5
+#define KVM_FEATURE_PVLOCK_KICK 6
/* 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.
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index 4c938da..c7b05fc 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -2099,6 +2099,7 @@ int kvm_dev_ioctl_check_extension(long ext)
case KVM_CAP_XSAVE:
case KVM_CAP_ASYNC_PF:
case KVM_CAP_GET_TSC_KHZ:
+ case KVM_CAP_PVLOCK_KICK:
r = 1;
break;
case KVM_CAP_COALESCED_MMIO:
@@ -2576,7 +2577,8 @@ static void do_cpuid_ent(struct kvm_cpuid_entry2 *entry, u32 function,
(1 << KVM_FEATURE_NOP_IO_DELAY) |
(1 << KVM_FEATURE_CLOCKSOURCE2) |
(1 << KVM_FEATURE_ASYNC_PF) |
- (1 << KVM_FEATURE_CLOCKSOURCE_STABLE_BIT);
+ (1 << KVM_FEATURE_CLOCKSOURCE_STABLE_BIT) |
+ (1 << KVM_FEATURE_PVLOCK_KICK);
if (sched_info_on())
entry->eax |= (1 << KVM_FEATURE_STEAL_TIME);
@@ -5304,6 +5306,29 @@ int kvm_hv_hypercall(struct kvm_vcpu *vcpu)
return 1;
}
+/*
+ * kvm_pv_kick_cpu_op: Kick a vcpu.
+ *
+ * @apicid - apicid of vcpu to be kicked.
+ */
+static void kvm_pv_kick_cpu_op(struct kvm *kvm, int apicid)
+{
+ struct kvm_vcpu *vcpu = NULL;
+ int i;
+
+ kvm_for_each_vcpu(i, vcpu, kvm) {
+ if (!kvm_apic_present(vcpu))
+ continue;
+
+ if (kvm_apic_match_dest(vcpu, 0, 0, apicid, 0))
+ break;
+ }
+ if (vcpu) {
+ kvm_make_request(KVM_REQ_PVLOCK_KICK, vcpu);
+ kvm_vcpu_kick(vcpu);
+ }
+}
+
int kvm_emulate_hypercall(struct kvm_vcpu *vcpu)
{
unsigned long nr, a0, a1, a2, a3, ret;
@@ -5340,6 +5365,10 @@ int kvm_emulate_hypercall(struct kvm_vcpu *vcpu)
case KVM_HC_MMU_OP:
r = kvm_pv_mmu_op(vcpu, a0, hc_gpa(vcpu, a1, a2), &ret);
break;
+ case KVM_HC_KICK_CPU:
+ kvm_pv_kick_cpu_op(vcpu->kvm, a0);
+ ret = 0;
+ break;
default:
ret = -KVM_ENOSYS;
break;
diff --git a/include/linux/kvm.h b/include/linux/kvm.h
index 68e67e5..63fb6b0 100644
--- a/include/linux/kvm.h
+++ b/include/linux/kvm.h
@@ -558,6 +558,7 @@ struct kvm_ppc_pvinfo {
#define KVM_CAP_PPC_PAPR 68
#define KVM_CAP_S390_GMAP 71
#define KVM_CAP_TSC_DEADLINE_TIMER 72
+#define KVM_CAP_PVLOCK_KICK 73
#ifdef KVM_CAP_IRQ_ROUTING
diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h
index d526231..3b1ae7b 100644
--- a/include/linux/kvm_host.h
+++ b/include/linux/kvm_host.h
@@ -50,6 +50,7 @@
#define KVM_REQ_APF_HALT 12
#define KVM_REQ_STEAL_UPDATE 13
#define KVM_REQ_NMI 14
+#define KVM_REQ_PVLOCK_KICK 15
#define KVM_USERSPACE_IRQ_SOURCE_ID 0
diff --git a/include/linux/kvm_para.h b/include/linux/kvm_para.h
index 47a070b..19f10bd 100644
--- a/include/linux/kvm_para.h
+++ b/include/linux/kvm_para.h
@@ -19,6 +19,7 @@
#define KVM_HC_MMU_OP 2
#define KVM_HC_FEATURES 3
#define KVM_HC_PPC_MAP_MAGIC_PAGE 4
+#define KVM_HC_KICK_CPU 5
/*
* hypercalls use architecture specific
--
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