From patchwork Tue Aug 21 11:26:35 2012 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Nikunj A. Dadhania" X-Patchwork-Id: 1354321 Return-Path: X-Original-To: patchwork-kvm@patchwork.kernel.org Delivered-To: patchwork-process-083081@patchwork2.kernel.org Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by patchwork2.kernel.org (Postfix) with ESMTP id 10C0BDFB34 for ; Tue, 21 Aug 2012 11:27:21 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752264Ab2HUL1S (ORCPT ); Tue, 21 Aug 2012 07:27:18 -0400 Received: from e28smtp06.in.ibm.com ([122.248.162.6]:45812 "EHLO e28smtp06.in.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751006Ab2HUL1Q (ORCPT ); Tue, 21 Aug 2012 07:27:16 -0400 Received: from /spool/local by e28smtp06.in.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted for from ; Tue, 21 Aug 2012 16:57:13 +0530 Received: from d28relay02.in.ibm.com (9.184.220.59) by e28smtp06.in.ibm.com (192.168.1.136) with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted; Tue, 21 Aug 2012 16:57:11 +0530 Received: from d28av03.in.ibm.com (d28av03.in.ibm.com [9.184.220.65]) by d28relay02.in.ibm.com (8.13.8/8.13.8/NCO v10.0) with ESMTP id q7LBRBi238600750 for ; Tue, 21 Aug 2012 16:57:11 +0530 Received: from d28av03.in.ibm.com (loopback [127.0.0.1]) by d28av03.in.ibm.com (8.14.4/8.13.1/NCO v10.0 AVout) with ESMTP id q7LBR8hr018995 for ; Tue, 21 Aug 2012 21:27:11 +1000 Received: from [9.124.35.230] (abhimanyu.in.ibm.com [9.124.35.230] (may be forged)) by d28av03.in.ibm.com (8.14.4/8.13.1/NCO v10.0 AVin) with ESMTP id q7LBR8WW018985; Tue, 21 Aug 2012 21:27:08 +1000 Subject: [PATCH v4 3/8] KVM Guest: Add VCPU running/pre-empted state for guest To: mtosatti@redhat.com, avi@redhat.com From: "Nikunj A. Dadhania" Cc: raghukt@linux.vnet.ibm.com, alex.shi@intel.com, kvm@vger.kernel.org, stefano.stabellini@eu.citrix.com, peterz@infradead.org, hpa@zytor.com, vsrivatsa@gmail.com, mingo@elte.hu Date: Tue, 21 Aug 2012 16:56:35 +0530 Message-ID: <20120821112630.3512.5109.stgit@abhimanyu> In-Reply-To: <20120821112346.3512.99814.stgit@abhimanyu.in.ibm.com> References: <20120821112346.3512.99814.stgit@abhimanyu.in.ibm.com> User-Agent: StGit/0.16-2-g0d85 MIME-Version: 1.0 x-cbid: 12082111-9574-0000-0000-00000412144B Sender: kvm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org From: Nikunj A. Dadhania The patch adds guest code for msr between guest and hypervisor. The msr will export the vcpu running/pre-empted information to the guest from host. This will enable guest to intelligently send ipi to running vcpus and set flag for pre-empted vcpus. This will prevent waiting for vcpus that are not running. Suggested-by: Peter Zijlstra Signed-off-by: Nikunj A. Dadhania --- arch/x86/include/asm/kvm_para.h | 13 +++++++++++++ arch/x86/kernel/kvm.c | 36 ++++++++++++++++++++++++++++++++++++ 2 files changed, 49 insertions(+), 0 deletions(-) -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html diff --git a/arch/x86/include/asm/kvm_para.h b/arch/x86/include/asm/kvm_para.h index 2f7712e..5dfb975 100644 --- a/arch/x86/include/asm/kvm_para.h +++ b/arch/x86/include/asm/kvm_para.h @@ -23,6 +23,7 @@ #define KVM_FEATURE_ASYNC_PF 4 #define KVM_FEATURE_STEAL_TIME 5 #define KVM_FEATURE_PV_EOI 6 +#define KVM_FEATURE_VCPU_STATE 7 /* 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. @@ -39,6 +40,7 @@ #define MSR_KVM_ASYNC_PF_EN 0x4b564d02 #define MSR_KVM_STEAL_TIME 0x4b564d03 #define MSR_KVM_PV_EOI_EN 0x4b564d04 +#define MSR_KVM_VCPU_STATE 0x4b564d05 struct kvm_steal_time { __u64 steal; @@ -51,6 +53,17 @@ struct kvm_steal_time { #define KVM_STEAL_VALID_BITS ((-1ULL << (KVM_STEAL_ALIGNMENT_BITS + 1))) #define KVM_STEAL_RESERVED_MASK (((1 << KVM_STEAL_ALIGNMENT_BITS) - 1 ) << 1) +struct kvm_vcpu_state { + __u64 state; + __u32 pad[14]; +}; +/* bits in vcpu_state->state */ +#define KVM_VCPU_STATE_IN_GUEST_MODE 0 +#define KVM_VCPU_STATE_SHOULD_FLUSH 1 + +#define KVM_VCPU_STATE_ALIGN_BITS 5 +#define KVM_VCPU_STATE_VALID_BITS ((-1ULL << (KVM_VCPU_STATE_ALIGN_BITS + 1))) + #define KVM_MAX_MMU_OP_BATCH 32 #define KVM_ASYNC_PF_ENABLED (1 << 0) diff --git a/arch/x86/kernel/kvm.c b/arch/x86/kernel/kvm.c index c1d61ee..37e6599 100644 --- a/arch/x86/kernel/kvm.c +++ b/arch/x86/kernel/kvm.c @@ -66,6 +66,9 @@ static DEFINE_PER_CPU(struct kvm_vcpu_pv_apf_data, apf_reason) __aligned(64); static DEFINE_PER_CPU(struct kvm_steal_time, steal_time) __aligned(64); static int has_steal_clock = 0; +DEFINE_PER_CPU(struct kvm_vcpu_state, vcpu_state) __aligned(64); +static int has_vcpu_state; + /* * No need for any "IO delay" on KVM */ @@ -302,6 +305,22 @@ static void kvm_guest_apic_eoi_write(u32 reg, u32 val) apic_write(APIC_EOI, APIC_EOI_ACK); } +static void kvm_register_vcpu_state(void) +{ + int cpu = smp_processor_id(); + struct kvm_vcpu_state *v_state; + + if (!has_vcpu_state) + return; + + v_state = &per_cpu(vcpu_state, cpu); + memset(v_state, 0, sizeof(*v_state)); + + wrmsrl(MSR_KVM_VCPU_STATE, (__pa(v_state) | KVM_MSR_ENABLED)); + printk(KERN_INFO "kvm-vcpustate: cpu %d, msr %lx\n", + cpu, __pa(v_state)); +} + void __cpuinit kvm_guest_cpu_init(void) { if (!kvm_para_available()) @@ -330,6 +349,9 @@ void __cpuinit kvm_guest_cpu_init(void) if (has_steal_clock) kvm_register_steal_time(); + + if (has_vcpu_state) + kvm_register_vcpu_state(); } static void kvm_pv_disable_apf(void) @@ -393,6 +415,14 @@ void kvm_disable_steal_time(void) wrmsr(MSR_KVM_STEAL_TIME, 0, 0); } +void kvm_disable_vcpu_state(void) +{ + if (!has_vcpu_state) + return; + + wrmsr(MSR_KVM_VCPU_STATE, 0, 0); +} + #ifdef CONFIG_SMP static void __init kvm_smp_prepare_boot_cpu(void) { @@ -410,6 +440,7 @@ static void __cpuinit kvm_guest_cpu_online(void *dummy) static void kvm_guest_cpu_offline(void *dummy) { + kvm_disable_vcpu_state(); kvm_disable_steal_time(); if (kvm_para_has_feature(KVM_FEATURE_PV_EOI)) wrmsrl(MSR_KVM_PV_EOI_EN, 0); @@ -469,6 +500,11 @@ void __init kvm_guest_init(void) if (kvm_para_has_feature(KVM_FEATURE_PV_EOI)) apic_set_eoi_write(kvm_guest_apic_eoi_write); +#ifdef CONFIG_PARAVIRT_TLB_FLUSH + if (kvm_para_has_feature(KVM_FEATURE_VCPU_STATE)) + has_vcpu_state = 1; +#endif + #ifdef CONFIG_SMP smp_ops.smp_prepare_boot_cpu = kvm_smp_prepare_boot_cpu; register_cpu_notifier(&kvm_cpu_notifier);