From patchwork Wed May 24 10:24:15 2017 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Paul Mackerras X-Patchwork-Id: 9745713 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id 1846F60209 for ; Wed, 24 May 2017 10:26:52 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 0F22F28936 for ; Wed, 24 May 2017 10:26:52 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 0406D2894A; Wed, 24 May 2017 10:26:52 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-6.9 required=2.0 tests=BAYES_00,RCVD_IN_DNSWL_HI autolearn=ham version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 4296F28936 for ; Wed, 24 May 2017 10:26:51 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S936758AbdEXK0s (ORCPT ); Wed, 24 May 2017 06:26:48 -0400 Received: from ozlabs.org ([103.22.144.67]:35347 "EHLO ozlabs.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S935643AbdEXK0m (ORCPT ); Wed, 24 May 2017 06:26:42 -0400 Received: by ozlabs.org (Postfix, from userid 1003) id 3wXpTq4vhLz9sNV; Wed, 24 May 2017 20:26:39 +1000 (AEST) Date: Wed, 24 May 2017 20:24:15 +1000 From: Paul Mackerras To: kvm@vger.kernel.org Cc: kvm-ppc@vger.kernel.org Subject: [PATCH 2/4] KVM: PPC: Book3S HV: Context-switch HFSCR between host and guest on POWER9 Message-ID: <20170524102415.GF18900@fergus.ozlabs.ibm.com> References: <20170524102231.GD18900@fergus.ozlabs.ibm.com> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <20170524102231.GD18900@fergus.ozlabs.ibm.com> User-Agent: Mutt/1.5.24 (2015-08-30) Sender: kvm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP This adds code to allow us to use a different value for the HFSCR (Hypervisor Facilities Status and Control Register) when running the guest from that which applies in the host. The reason for doing this is to allow us to trap the msgsndp instruction and related operations in future so that they can be virtualized. We also save the value of HFSCR when a hypervisor facility unavailable interrupt occurs, because the high byte of HFSCR indicates which facility the guest attempted to access. We save and restore the host value on guest entry/exit because some bits of it affect host userspace execution. We only do all this on POWER9, not on POWER8, because we are not intending to virtualize any of the facilities controlled by HFSCR on POWER8. In particular, the HFSCR bit that controls execution of msgsndp and related operations does not exist on POWER8. The HFSCR doesn't exist at all on POWER7. Signed-off-by: Paul Mackerras --- arch/powerpc/include/asm/kvm_host.h | 1 + arch/powerpc/kernel/asm-offsets.c | 1 + arch/powerpc/kvm/book3s_hv.c | 10 ++++++++++ arch/powerpc/kvm/book3s_hv_rmhandlers.S | 15 +++++++++++++++ 4 files changed, 27 insertions(+) diff --git a/arch/powerpc/include/asm/kvm_host.h b/arch/powerpc/include/asm/kvm_host.h index 3f879c8..d3aae32 100644 --- a/arch/powerpc/include/asm/kvm_host.h +++ b/arch/powerpc/include/asm/kvm_host.h @@ -566,6 +566,7 @@ struct kvm_vcpu_arch { ulong wort; ulong tid; ulong psscr; + ulong hfscr; ulong shadow_srr1; #endif u32 vrsave; /* also USPRG0 */ diff --git a/arch/powerpc/kernel/asm-offsets.c b/arch/powerpc/kernel/asm-offsets.c index 709e234..562d291f 100644 --- a/arch/powerpc/kernel/asm-offsets.c +++ b/arch/powerpc/kernel/asm-offsets.c @@ -542,6 +542,7 @@ int main(void) OFFSET(VCPU_WORT, kvm_vcpu, arch.wort); OFFSET(VCPU_TID, kvm_vcpu, arch.tid); OFFSET(VCPU_PSSCR, kvm_vcpu, arch.psscr); + OFFSET(VCPU_HFSCR, kvm_vcpu, arch.hfscr); OFFSET(VCORE_ENTRY_EXIT, kvmppc_vcore, entry_exit_map); OFFSET(VCORE_IN_GUEST, kvmppc_vcore, in_guest); OFFSET(VCORE_NAPPING_THREADS, kvmppc_vcore, napping_threads); diff --git a/arch/powerpc/kvm/book3s_hv.c b/arch/powerpc/kvm/book3s_hv.c index 1cd194e..de1a3f1a 100644 --- a/arch/powerpc/kvm/book3s_hv.c +++ b/arch/powerpc/kvm/book3s_hv.c @@ -1813,6 +1813,16 @@ static struct kvm_vcpu *kvmppc_core_vcpu_create_hv(struct kvm *kvm, vcpu->arch.busy_preempt = TB_NIL; vcpu->arch.intr_msr = MSR_SF | MSR_ME; + /* + * Set the default HFSCR for the guest from the host value. + * This value is only used on POWER9. + * On POWER9 DD1, TM doesn't work, so we make sure to + * prevent the guest from using it. + */ + vcpu->arch.hfscr = mfspr(SPRN_HFSCR); + if (!cpu_has_feature(CPU_FTR_TM)) + vcpu->arch.hfscr &= ~HFSCR_TM; + kvmppc_mmu_book3s_hv_init(vcpu); vcpu->arch.state = KVMPPC_VCPU_NOTREADY; diff --git a/arch/powerpc/kvm/book3s_hv_rmhandlers.S b/arch/powerpc/kvm/book3s_hv_rmhandlers.S index e7a2c89..4485b7a 100644 --- a/arch/powerpc/kvm/book3s_hv_rmhandlers.S +++ b/arch/powerpc/kvm/book3s_hv_rmhandlers.S @@ -554,6 +554,7 @@ END_FTR_SECTION_IFSET(CPU_FTR_ARCH_207S) #define STACK_SLOT_TID (112-16) #define STACK_SLOT_PSSCR (112-24) #define STACK_SLOT_PID (112-32) +#define STACK_SLOT_HFSCR (112-40) .global kvmppc_hv_entry kvmppc_hv_entry: @@ -754,9 +755,11 @@ BEGIN_FTR_SECTION mfspr r5, SPRN_TIDR mfspr r6, SPRN_PSSCR mfspr r7, SPRN_PID + mfspr r8, SPRN_HFSCR std r5, STACK_SLOT_TID(r1) std r6, STACK_SLOT_PSSCR(r1) std r7, STACK_SLOT_PID(r1) + std r8, STACK_SLOT_HFSCR(r1) END_FTR_SECTION_IFSET(CPU_FTR_ARCH_300) BEGIN_FTR_SECTION @@ -900,8 +903,10 @@ FTR_SECTION_ELSE ld r5, VCPU_TID(r4) ld r6, VCPU_PSSCR(r4) oris r6, r6, PSSCR_EC@h /* This makes stop trap to HV */ + ld r7, VCPU_HFSCR(r4) mtspr SPRN_TIDR, r5 mtspr SPRN_PSSCR, r6 + mtspr SPRN_HFSCR, r7 ALT_FTR_SECTION_END_IFCLR(CPU_FTR_ARCH_300) 8: @@ -1276,6 +1281,13 @@ END_FTR_SECTION_IFSET(CPU_FTR_HAS_PPR) beq 4f b guest_exit_cont 3: + /* If it's a hypervisor facility unavailable interrupt, save HFSCR */ + cmpwi r12, BOOK3S_INTERRUPT_H_FAC_UNAVAIL + bne 14f + mfspr r3, SPRN_HFSCR + std r3, VCPU_HFSCR(r9) + b guest_exit_cont +14: /* External interrupt ? */ cmpwi r12, BOOK3S_INTERRUPT_EXTERNAL bne+ guest_exit_cont @@ -1519,6 +1531,9 @@ FTR_SECTION_ELSE rldicl r6, r6, 4, 50 /* r6 &= PSSCR_GUEST_VIS */ rotldi r6, r6, 60 std r6, VCPU_PSSCR(r9) + /* Restore host HFSCR value */ + ld r7, STACK_SLOT_HFSCR(r1) + mtspr SPRN_HFSCR, r7 ALT_FTR_SECTION_END_IFCLR(CPU_FTR_ARCH_300) /* * Restore various registers to 0, where non-zero values