From: James Hogan <james.hogan@imgtec.com> To: <linux-mips@linux-mips.org>, <kvm@vger.kernel.org> Cc: "James Hogan" <james.hogan@imgtec.com>, "Paolo Bonzini" <pbonzini@redhat.com>, "Radim Krčmář" <rkrcmar@redhat.com>, "Ralf Baechle" <ralf@linux-mips.org> Subject: [PATCH v2 10/33] KVM: MIPS: Update kvm_lose_fpu() for VZ Date: Tue, 14 Mar 2017 10:15:17 +0000 [thread overview] Message-ID: <7e134450e015643a1b07bb65657fc4acaabcc22b.1489485940.git-series.james.hogan@imgtec.com> (raw) In-Reply-To: <cover.26e10ec77a4ed0d3177ccf4fabf57bc95ea030f8.1489485940.git-series.james.hogan@imgtec.com> Update the implementation of kvm_lose_fpu() for VZ, where there is no need to enable the FPU/MSA in the root context if the FPU/MSA state is loaded but disabled in the guest context. The trap & emulate implementation needs to disable FPU/MSA in the root context when the guest disables them in order to catch the COP1 unusable or MSA disabled exception when they're used and pass it on to the guest. For VZ however as long as the context is loaded and enabled in the root context, the guest can enable and disable it in the guest context without the hypervisor having to do much, and will take guest exceptions without hypervisor intervention if used without being enabled in the guest context. Signed-off-by: James Hogan <james.hogan@imgtec.com> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: "Radim Krčmář" <rkrcmar@redhat.com> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: linux-mips@linux-mips.org Cc: kvm@vger.kernel.org --- arch/mips/kvm/mips.c | 20 ++++++++++++-------- 1 file changed, 12 insertions(+), 8 deletions(-) diff --git a/arch/mips/kvm/mips.c b/arch/mips/kvm/mips.c index 15a1b1716c2e..a743f67378ba 100644 --- a/arch/mips/kvm/mips.c +++ b/arch/mips/kvm/mips.c @@ -1527,16 +1527,18 @@ void kvm_drop_fpu(struct kvm_vcpu *vcpu) void kvm_lose_fpu(struct kvm_vcpu *vcpu) { /* - * FPU & MSA get disabled in root context (hardware) when it is disabled - * in guest context (software), but the register state in the hardware - * may still be in use. This is why we explicitly re-enable the hardware - * before saving. + * With T&E, FPU & MSA get disabled in root context (hardware) when it + * is disabled in guest context (software), but the register state in + * the hardware may still be in use. + * This is why we explicitly re-enable the hardware before saving. */ preempt_disable(); if (cpu_has_msa && vcpu->arch.aux_inuse & KVM_MIPS_AUX_MSA) { - set_c0_config5(MIPS_CONF5_MSAEN); - enable_fpu_hazard(); + if (!IS_ENABLED(CONFIG_KVM_MIPS_VZ)) { + set_c0_config5(MIPS_CONF5_MSAEN); + enable_fpu_hazard(); + } __kvm_save_msa(&vcpu->arch); trace_kvm_aux(vcpu, KVM_TRACE_AUX_SAVE, KVM_TRACE_AUX_FPU_MSA); @@ -1549,8 +1551,10 @@ void kvm_lose_fpu(struct kvm_vcpu *vcpu) } vcpu->arch.aux_inuse &= ~(KVM_MIPS_AUX_FPU | KVM_MIPS_AUX_MSA); } else if (vcpu->arch.aux_inuse & KVM_MIPS_AUX_FPU) { - set_c0_status(ST0_CU1); - enable_fpu_hazard(); + if (!IS_ENABLED(CONFIG_KVM_MIPS_VZ)) { + set_c0_status(ST0_CU1); + enable_fpu_hazard(); + } __kvm_save_fpu(&vcpu->arch); vcpu->arch.aux_inuse &= ~KVM_MIPS_AUX_FPU; -- git-series 0.8.10
WARNING: multiple messages have this Message-ID (diff)
From: James Hogan <james.hogan@imgtec.com> To: linux-mips@linux-mips.org, kvm@vger.kernel.org Cc: "James Hogan" <james.hogan@imgtec.com>, "Paolo Bonzini" <pbonzini@redhat.com>, "Radim Krčmář" <rkrcmar@redhat.com>, "Ralf Baechle" <ralf@linux-mips.org> Subject: [PATCH v2 10/33] KVM: MIPS: Update kvm_lose_fpu() for VZ Date: Tue, 14 Mar 2017 10:15:17 +0000 [thread overview] Message-ID: <7e134450e015643a1b07bb65657fc4acaabcc22b.1489485940.git-series.james.hogan@imgtec.com> (raw) Message-ID: <20170314101517.RBktxHP5wUOSrpIPda9fzIwMj2fK0t3PgXBXk1Q2bws@z> (raw) In-Reply-To: <cover.26e10ec77a4ed0d3177ccf4fabf57bc95ea030f8.1489485940.git-series.james.hogan@imgtec.com> Update the implementation of kvm_lose_fpu() for VZ, where there is no need to enable the FPU/MSA in the root context if the FPU/MSA state is loaded but disabled in the guest context. The trap & emulate implementation needs to disable FPU/MSA in the root context when the guest disables them in order to catch the COP1 unusable or MSA disabled exception when they're used and pass it on to the guest. For VZ however as long as the context is loaded and enabled in the root context, the guest can enable and disable it in the guest context without the hypervisor having to do much, and will take guest exceptions without hypervisor intervention if used without being enabled in the guest context. Signed-off-by: James Hogan <james.hogan@imgtec.com> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: "Radim Krčmář" <rkrcmar@redhat.com> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: linux-mips@linux-mips.org Cc: kvm@vger.kernel.org --- arch/mips/kvm/mips.c | 20 ++++++++++++-------- 1 file changed, 12 insertions(+), 8 deletions(-) diff --git a/arch/mips/kvm/mips.c b/arch/mips/kvm/mips.c index 15a1b1716c2e..a743f67378ba 100644 --- a/arch/mips/kvm/mips.c +++ b/arch/mips/kvm/mips.c @@ -1527,16 +1527,18 @@ void kvm_drop_fpu(struct kvm_vcpu *vcpu) void kvm_lose_fpu(struct kvm_vcpu *vcpu) { /* - * FPU & MSA get disabled in root context (hardware) when it is disabled - * in guest context (software), but the register state in the hardware - * may still be in use. This is why we explicitly re-enable the hardware - * before saving. + * With T&E, FPU & MSA get disabled in root context (hardware) when it + * is disabled in guest context (software), but the register state in + * the hardware may still be in use. + * This is why we explicitly re-enable the hardware before saving. */ preempt_disable(); if (cpu_has_msa && vcpu->arch.aux_inuse & KVM_MIPS_AUX_MSA) { - set_c0_config5(MIPS_CONF5_MSAEN); - enable_fpu_hazard(); + if (!IS_ENABLED(CONFIG_KVM_MIPS_VZ)) { + set_c0_config5(MIPS_CONF5_MSAEN); + enable_fpu_hazard(); + } __kvm_save_msa(&vcpu->arch); trace_kvm_aux(vcpu, KVM_TRACE_AUX_SAVE, KVM_TRACE_AUX_FPU_MSA); @@ -1549,8 +1551,10 @@ void kvm_lose_fpu(struct kvm_vcpu *vcpu) } vcpu->arch.aux_inuse &= ~(KVM_MIPS_AUX_FPU | KVM_MIPS_AUX_MSA); } else if (vcpu->arch.aux_inuse & KVM_MIPS_AUX_FPU) { - set_c0_status(ST0_CU1); - enable_fpu_hazard(); + if (!IS_ENABLED(CONFIG_KVM_MIPS_VZ)) { + set_c0_status(ST0_CU1); + enable_fpu_hazard(); + } __kvm_save_fpu(&vcpu->arch); vcpu->arch.aux_inuse &= ~KVM_MIPS_AUX_FPU; -- git-series 0.8.10
next prev parent reply other threads:[~2017-03-14 10:20 UTC|newest] Thread overview: 72+ messages / expand[flat|nested] mbox.gz Atom feed top 2017-03-14 10:15 [PATCH v2 0/33] KVM: MIPS: Add VZ support James Hogan 2017-03-14 10:15 ` James Hogan 2017-03-14 10:15 ` [PATCH v2 1/33] MIPS: Add defs & probing of UFR James Hogan 2017-03-14 10:15 ` James Hogan 2017-03-14 10:15 ` [PATCH v2 2/33] MIPS: Separate MAAR V bit into VL and VH for XPA James Hogan 2017-03-14 10:15 ` James Hogan 2017-03-14 10:15 ` [PATCH v2 3/33] MIPS: Probe guest CP0_UserLocal James Hogan 2017-03-14 10:15 ` James Hogan 2017-03-14 10:15 ` [PATCH v2 4/33] MIPS: Probe guest MVH James Hogan 2017-03-14 10:15 ` James Hogan 2017-03-14 10:15 ` [PATCH v2 5/33] MIPS: Add some missing guest CP0 accessors & defs James Hogan 2017-03-14 10:15 ` James Hogan 2017-03-14 10:15 ` [PATCH v2 6/33] MIPS: asm/tlb.h: Add UNIQUE_GUEST_ENTRYHI() macro James Hogan 2017-03-14 10:15 ` James Hogan 2017-03-14 10:15 ` [PATCH v2 7/33] KVM: MIPS: Implement HYPCALL emulation James Hogan 2017-03-14 10:15 ` James Hogan 2017-03-14 10:15 ` [PATCH v2 8/33] KVM: MIPS/Emulate: De-duplicate MMIO emulation James Hogan 2017-03-14 10:15 ` James Hogan 2017-03-14 10:15 ` [PATCH v2 9/33] KVM: MIPS/Emulate: Implement 64-bit " James Hogan 2017-03-14 10:15 ` James Hogan 2017-03-14 10:15 ` James Hogan [this message] 2017-03-14 10:15 ` [PATCH v2 10/33] KVM: MIPS: Update kvm_lose_fpu() for VZ James Hogan 2017-03-14 10:15 ` [PATCH v2 11/33] KVM: MIPS: Extend counters & events for VZ GExcCodes James Hogan 2017-03-14 10:15 ` James Hogan 2017-03-14 10:15 ` [PATCH v2 12/33] KVM: MIPS: Add VZ & TE capabilities James Hogan 2017-03-14 10:15 ` James Hogan 2017-03-14 10:15 ` [PATCH v2 13/33] KVM: MIPS: Add 64BIT capability James Hogan 2017-03-14 10:15 ` James Hogan 2017-03-14 10:15 ` [PATCH v2 14/33] KVM: MIPS: Init timer frequency from callback James Hogan 2017-03-14 10:15 ` James Hogan 2017-03-14 10:15 ` [PATCH v2 15/33] KVM: MIPS: Add callback to check extension James Hogan 2017-03-14 10:15 ` James Hogan 2017-03-14 10:15 ` [PATCH v2 16/33] KVM: MIPS: Add hardware_{enable,disable} callback James Hogan 2017-03-14 10:15 ` James Hogan 2017-03-14 10:15 ` [PATCH v2 17/33] KVM: MIPS: Add guest exit exception callback James Hogan 2017-03-14 10:15 ` James Hogan 2017-03-14 10:15 ` [PATCH v2 18/33] KVM: MIPS: Abstract guest CP0 register access for VZ James Hogan 2017-03-14 10:15 ` James Hogan 2017-03-14 10:15 ` [PATCH v2 19/33] KVM: MIPS/Entry: Update entry code to support VZ James Hogan 2017-03-14 10:15 ` James Hogan 2017-03-14 10:15 ` [PATCH v2 20/33] KVM: MIPS/TLB: Add VZ TLB management James Hogan 2017-03-14 10:15 ` James Hogan 2017-03-14 10:15 ` [PATCH v2 21/33] KVM: MIPS/Emulate: Update CP0_Compare emulation for VZ James Hogan 2017-03-14 10:15 ` James Hogan 2017-03-14 10:15 ` [PATCH v2 22/33] KVM: MIPS/Emulate: Drop CACHE " James Hogan 2017-03-14 10:15 ` James Hogan 2017-03-14 10:15 ` [PATCH v2 23/33] KVM: MIPS: Update exit handler " James Hogan 2017-03-14 10:15 ` James Hogan 2017-03-14 10:15 ` [PATCH v2 24/33] KVM: MIPS: Implement VZ support James Hogan 2017-03-14 10:15 ` James Hogan 2017-03-14 10:15 ` [PATCH v2 25/33] KVM: MIPS: Add VZ support to build system James Hogan 2017-03-14 10:15 ` James Hogan 2017-03-16 11:40 ` kbuild test robot 2017-03-16 11:40 ` kbuild test robot 2017-03-16 12:50 ` James Hogan 2017-03-14 10:15 ` [PATCH v2 26/33] KVM: MIPS/VZ: Support guest CP0_BadInstr[P] James Hogan 2017-03-14 10:15 ` James Hogan 2017-03-14 10:15 ` [PATCH v2 27/33] KVM: MIPS/VZ: Support guest CP0_[X]ContextConfig James Hogan 2017-03-14 10:15 ` James Hogan 2017-03-14 10:15 ` [PATCH v2 28/33] KVM: MIPS/VZ: Support guest segmentation control James Hogan 2017-03-14 10:15 ` James Hogan 2017-03-14 10:15 ` [PATCH v2 29/33] KVM: MIPS/VZ: Support guest hardware page table walker James Hogan 2017-03-14 10:15 ` James Hogan 2017-03-14 10:15 ` [PATCH v2 30/33] KVM: MIPS/VZ: Support guest load-linked bit James Hogan 2017-03-14 10:15 ` James Hogan 2017-03-14 10:15 ` [PATCH v2 31/33] KVM: MIPS/VZ: Emulate MAARs when necessary James Hogan 2017-03-14 10:15 ` James Hogan 2017-03-14 10:15 ` [PATCH v2 32/33] KVM: MIPS/VZ: Support hardware guest timer James Hogan 2017-03-14 10:15 ` James Hogan 2017-03-14 10:15 ` [PATCH v2 33/33] KVM: MIPS/VZ: Trace guest mode changes James Hogan 2017-03-14 10:15 ` James Hogan 2017-03-15 16:32 ` [PATCH v2 0/33] KVM: MIPS: Add VZ support Ralf Baechle
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