From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from ozlabs.org (ozlabs.org [IPv6:2401:3900:2:1::2]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id 3tKqP23dcMzDvt1 for ; Fri, 18 Nov 2016 18:28:54 +1100 (AEDT) From: Paul Mackerras To: kvm@vger.kernel.org, kvm-ppc@vger.kernel.org, linuxppc-dev@ozlabs.org Subject: [PATCH 10/13] KVM: PPC: Book3S HV: Use msgsnd for IPIs to other cores on POWER9 Date: Fri, 18 Nov 2016 18:28:39 +1100 Message-Id: <1479454122-26994-11-git-send-email-paulus@ozlabs.org> In-Reply-To: <1479454122-26994-1-git-send-email-paulus@ozlabs.org> References: <1479454122-26994-1-git-send-email-paulus@ozlabs.org> List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , On POWER9, the msgsnd instruction is able to send interrupts to other cores, as well as other threads on the local core. Since msgsnd is generally simpler and faster than sending an IPI via the XICS, we use msgsnd for all IPIs sent by KVM on POWER9. Signed-off-by: Paul Mackerras --- arch/powerpc/kvm/book3s_hv.c | 11 ++++++++++- arch/powerpc/kvm/book3s_hv_builtin.c | 10 ++++++++-- 2 files changed, 18 insertions(+), 3 deletions(-) diff --git a/arch/powerpc/kvm/book3s_hv.c b/arch/powerpc/kvm/book3s_hv.c index 8395a7f..ace89df 100644 --- a/arch/powerpc/kvm/book3s_hv.c +++ b/arch/powerpc/kvm/book3s_hv.c @@ -147,12 +147,21 @@ static inline struct kvm_vcpu *next_runnable_thread(struct kvmppc_vcore *vc, static bool kvmppc_ipi_thread(int cpu) { + unsigned long msg = PPC_DBELL_TYPE(PPC_DBELL_SERVER); + + /* On POWER9 we can use msgsnd to IPI any cpu */ + if (cpu_has_feature(CPU_FTR_ARCH_300)) { + msg |= get_hard_smp_processor_id(cpu); + smp_mb(); + __asm__ __volatile__ (PPC_MSGSND(%0) : : "r" (msg)); + return true; + } + /* On POWER8 for IPIs to threads in the same core, use msgsnd */ if (cpu_has_feature(CPU_FTR_ARCH_207S)) { preempt_disable(); if (cpu_first_thread_sibling(cpu) == cpu_first_thread_sibling(smp_processor_id())) { - unsigned long msg = PPC_DBELL_TYPE(PPC_DBELL_SERVER); msg |= cpu_thread_in_core(cpu); smp_mb(); __asm__ __volatile__ (PPC_MSGSND(%0) : : "r" (msg)); diff --git a/arch/powerpc/kvm/book3s_hv_builtin.c b/arch/powerpc/kvm/book3s_hv_builtin.c index 0c84d6b..37ed045 100644 --- a/arch/powerpc/kvm/book3s_hv_builtin.c +++ b/arch/powerpc/kvm/book3s_hv_builtin.c @@ -205,12 +205,18 @@ static inline void rm_writeb(unsigned long paddr, u8 val) void kvmhv_rm_send_ipi(int cpu) { unsigned long xics_phys; + unsigned long msg = PPC_DBELL_TYPE(PPC_DBELL_SERVER); - /* On POWER8 for IPIs to threads in the same core, use msgsnd */ + /* On POWER9 we can use msgsnd for any destination cpu. */ + if (cpu_has_feature(CPU_FTR_ARCH_300)) { + msg |= get_hard_smp_processor_id(cpu); + __asm__ __volatile__ (PPC_MSGSND(%0) : : "r" (msg)); + return; + } + /* On POWER8 for IPIs to threads in the same core, use msgsnd. */ if (cpu_has_feature(CPU_FTR_ARCH_207S) && cpu_first_thread_sibling(cpu) == cpu_first_thread_sibling(raw_smp_processor_id())) { - unsigned long msg = PPC_DBELL_TYPE(PPC_DBELL_SERVER); msg |= cpu_thread_in_core(cpu); __asm__ __volatile__ (PPC_MSGSND(%0) : : "r" (msg)); return; -- 2.7.4