KVM: PPC: Keep SRR1 flags around in shadow_msr

SRR1 stores more information that just the MSR value. It also stores
valuable information about the type of interrupt we received, for
example whether the storage interrupt we just got was because of a
missing htab entry or not.

We use that information to speed up the exit path.

Now if we get preempted before we can interpret the shadow_msr values,
we get into vcpu_put which then calls the MSR handler, which then sets
all the SRR1 information bits in shadow_msr to 0. Great.

So let's preserve the SRR1 specific bits in shadow_msr whenever we set
the MSR. They don't hurt.

Signed-off-by: Alexander Graf <agraf@suse.de>
Signed-off-by: Avi Kivity <avi@redhat.com>

diff --git a/arch/powerpc/include/asm/kvm_host.h b/arch/powerpc/include/asm/kvm_host.h
index c30a70c6b93155904157bbb028bea2bdfca2a383..715aa6baf6f0202f64239a793a40818c795e951b 100644 (file)
--- a/arch/powerpc/include/asm/kvm_host.h
+++ b/arch/powerpc/include/asm/kvm_host.h
@@ -198,6 +198,7 @@ struct kvm_vcpu_arch {
        ulong msr;
 #ifdef CONFIG_PPC64
        ulong shadow_msr;
+       ulong shadow_srr1;
        ulong hflags;
        ulong guest_owned_ext;
 #endif

diff --git a/arch/powerpc/kernel/asm-offsets.c b/arch/powerpc/kernel/asm-offsets.c
index ee9935442f0eedf593ae7d01d9020a2f14d4e9cb..957ceb7059c57a8a2bd7c5ffd9330a361baaf160 100644 (file)
--- a/arch/powerpc/kernel/asm-offsets.c
+++ b/arch/powerpc/kernel/asm-offsets.c
@@ -433,6 +433,7 @@ int main(void)
        DEFINE(VCPU_HOST_R2, offsetof(struct kvm_vcpu, arch.host_r2));
        DEFINE(VCPU_HOST_MSR, offsetof(struct kvm_vcpu, arch.host_msr));
        DEFINE(VCPU_SHADOW_MSR, offsetof(struct kvm_vcpu, arch.shadow_msr));
+       DEFINE(VCPU_SHADOW_SRR1, offsetof(struct kvm_vcpu, arch.shadow_srr1));
        DEFINE(VCPU_TRAMPOLINE_LOWMEM, offsetof(struct kvm_vcpu, arch.trampoline_lowmem));
        DEFINE(VCPU_TRAMPOLINE_ENTER, offsetof(struct kvm_vcpu, arch.trampoline_enter));
        DEFINE(VCPU_HIGHMEM_HANDLER, offsetof(struct kvm_vcpu, arch.highmem_handler));

diff --git a/arch/powerpc/kvm/book3s.c b/arch/powerpc/kvm/book3s.c
index 2cb181396f827912998fdd077209db1cdffc86f4..58f5200fc09bb0fd09de04a373b4817b03c02f75 100644 (file)
--- a/arch/powerpc/kvm/book3s.c
+++ b/arch/powerpc/kvm/book3s.c
@@ -524,14 +524,14 @@ int kvmppc_handle_pagefault(struct kvm_run *run, struct kvm_vcpu *vcpu,
                /* Page not found in guest PTE entries */
                vcpu->arch.dear = vcpu->arch.fault_dear;
                to_book3s(vcpu)->dsisr = vcpu->arch.fault_dsisr;
-               vcpu->arch.msr |= (vcpu->arch.shadow_msr & 0x00000000f8000000ULL);
+               vcpu->arch.msr |= (vcpu->arch.shadow_srr1 & 0x00000000f8000000ULL);
                kvmppc_book3s_queue_irqprio(vcpu, vec);
        } else if (page_found == -EPERM) {
                /* Storage protection */
                vcpu->arch.dear = vcpu->arch.fault_dear;
                to_book3s(vcpu)->dsisr = vcpu->arch.fault_dsisr & ~DSISR_NOHPTE;
                to_book3s(vcpu)->dsisr |= DSISR_PROTFAULT;
-               vcpu->arch.msr |= (vcpu->arch.shadow_msr & 0x00000000f8000000ULL);
+               vcpu->arch.msr |= (vcpu->arch.shadow_srr1 & 0x00000000f8000000ULL);
                kvmppc_book3s_queue_irqprio(vcpu, vec);
        } else if (page_found == -EINVAL) {
                /* Page not found in guest SLB */
@@ -693,7 +693,7 @@ int kvmppc_handle_exit(struct kvm_run *run, struct kvm_vcpu *vcpu,
        case BOOK3S_INTERRUPT_INST_STORAGE:
                vcpu->stat.pf_instruc++;
                /* only care about PTEG not found errors, but leave NX alone */
-               if (vcpu->arch.shadow_msr & 0x40000000) {
+               if (vcpu->arch.shadow_srr1 & 0x40000000) {
                        r = kvmppc_handle_pagefault(run, vcpu, vcpu->arch.pc, exit_nr);
                        vcpu->stat.sp_instruc++;
                } else if (vcpu->arch.mmu.is_dcbz32(vcpu) &&
@@ -705,7 +705,7 @@ int kvmppc_handle_exit(struct kvm_run *run, struct kvm_vcpu *vcpu,
                         */
                        kvmppc_mmu_pte_flush(vcpu, vcpu->arch.pc, ~0xFFFULL);
                } else {
-                       vcpu->arch.msr |= (vcpu->arch.shadow_msr & 0x58000000);
+                       vcpu->arch.msr |= vcpu->arch.shadow_srr1 & 0x58000000;
                        kvmppc_book3s_queue_irqprio(vcpu, exit_nr);
                        kvmppc_mmu_pte_flush(vcpu, vcpu->arch.pc, ~0xFFFULL);
                        r = RESUME_GUEST;
@@ -753,7 +753,7 @@ int kvmppc_handle_exit(struct kvm_run *run, struct kvm_vcpu *vcpu,
                enum emulation_result er;
                ulong flags;
 
-               flags = (vcpu->arch.shadow_msr & 0x1f0000ull);
+               flags = vcpu->arch.shadow_srr1 & 0x1f0000ull;
 
                if (vcpu->arch.msr & MSR_PR) {
 #ifdef EXIT_DEBUG
@@ -808,7 +808,8 @@ int kvmppc_handle_exit(struct kvm_run *run, struct kvm_vcpu *vcpu,
                break;
        default:
                /* Ugh - bork here! What did we get? */
-               printk(KERN_EMERG "exit_nr=0x%x | pc=0x%lx | msr=0x%lx\n", exit_nr, vcpu->arch.pc, vcpu->arch.shadow_msr);
+               printk(KERN_EMERG "exit_nr=0x%x | pc=0x%lx | msr=0x%lx\n",
+                       exit_nr, vcpu->arch.pc, vcpu->arch.shadow_srr1);
                r = RESUME_HOST;
                BUG();
                break;

diff --git a/arch/powerpc/kvm/book3s_64_interrupts.S b/arch/powerpc/kvm/book3s_64_interrupts.S
index 2ff0b2137e6f338ebcbedf82fc9db12298428086..c1584d0cbce82d3ca9f3dd0565d6d5adacbfc3c7 100644 (file)
--- a/arch/powerpc/kvm/book3s_64_interrupts.S
+++ b/arch/powerpc/kvm/book3s_64_interrupts.S
@@ -169,7 +169,7 @@ kvmppc_handler_highmem:
        stw     r0, VCPU_LAST_INST(r7)
 
        std     r3, VCPU_PC(r7)
-       std     r4, VCPU_SHADOW_MSR(r7)
+       std     r4, VCPU_SHADOW_SRR1(r7)
        std     r5, VCPU_FAULT_DEAR(r7)
        std     r6, VCPU_FAULT_DSISR(r7)