diff options
| author | Benjamin Herrenschmidt <benh@kernel.crashing.org> | 2012-03-13 21:52:44 +0000 |
|---|---|---|
| committer | Avi Kivity <avi@redhat.com> | 2012-04-08 14:02:39 +0300 |
| commit | bbcc9c06695243ea23d30de36842df9200c33857 (patch) | |
| tree | 530a126fb2f774f5b4dd2cb4a8b0d042d79a4323 | |
| parent | 966cd0f3bdd422f0b10686fb59d0d456fbbb6398 (diff) | |
| download | linux-bbcc9c06695243ea23d30de36842df9200c33857.tar.bz2 | |
powerpc/kvm: Fix magic page vs. 32-bit RTAS on ppc64
When the kernel calls into RTAS, it switches to 32-bit mode. The
magic page was is longer accessible in that case, causing the
patched instructions in the RTAS call wrapper to crash.
This fixes it by making available a 32-bit mapping of the magic
page in that case. This mapping is flushed whenever we switch
the kernel back to 64-bit mode.
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
[agraf: add a check if the magic page is mapped]
Signed-off-by: Alexander Graf <agraf@suse.de>
Signed-off-by: Avi Kivity <avi@redhat.com>
| -rw-r--r-- | arch/powerpc/kvm/book3s.c | 3 | ||||
| -rw-r--r-- | arch/powerpc/kvm/book3s_pr.c | 18 |
2 files changed, 21 insertions, 0 deletions
diff --git a/arch/powerpc/kvm/book3s.c b/arch/powerpc/kvm/book3s.c index c8ead7b9f03b..3f2a8360c857 100644 --- a/arch/powerpc/kvm/book3s.c +++ b/arch/powerpc/kvm/book3s.c @@ -291,6 +291,9 @@ pfn_t kvmppc_gfn_to_pfn(struct kvm_vcpu *vcpu, gfn_t gfn) { ulong mp_pa = vcpu->arch.magic_page_pa; + if (!(vcpu->arch.shared->msr & MSR_SF)) + mp_pa = (uint32_t)mp_pa; + /* Magic page override */ if (unlikely(mp_pa) && unlikely(((gfn << PAGE_SHIFT) & KVM_PAM) == diff --git a/arch/powerpc/kvm/book3s_pr.c b/arch/powerpc/kvm/book3s_pr.c index 912e10fbf6ef..dba282e5093f 100644 --- a/arch/powerpc/kvm/book3s_pr.c +++ b/arch/powerpc/kvm/book3s_pr.c @@ -145,6 +145,21 @@ void kvmppc_set_msr(struct kvm_vcpu *vcpu, u64 msr) } } + /* + * When switching from 32 to 64-bit, we may have a stale 32-bit + * magic page around, we need to flush it. Typically 32-bit magic + * page will be instanciated when calling into RTAS. Note: We + * assume that such transition only happens while in kernel mode, + * ie, we never transition from user 32-bit to kernel 64-bit with + * a 32-bit magic page around. + */ + if (vcpu->arch.magic_page_pa && + !(old_msr & MSR_PR) && !(old_msr & MSR_SF) && (msr & MSR_SF)) { + /* going from RTAS to normal kernel code */ + kvmppc_mmu_pte_flush(vcpu, (uint32_t)vcpu->arch.magic_page_pa, + ~0xFFFUL); + } + /* Preload FPU if it's enabled */ if (vcpu->arch.shared->msr & MSR_FP) kvmppc_handle_ext(vcpu, BOOK3S_INTERRUPT_FP_UNAVAIL, MSR_FP); @@ -252,6 +267,9 @@ static int kvmppc_visible_gfn(struct kvm_vcpu *vcpu, gfn_t gfn) { ulong mp_pa = vcpu->arch.magic_page_pa; + if (!(vcpu->arch.shared->msr & MSR_SF)) + mp_pa = (uint32_t)mp_pa; + if (unlikely(mp_pa) && unlikely((mp_pa & KVM_PAM) >> PAGE_SHIFT == gfn)) { return 1; |