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| author | James Hogan <james.hogan@imgtec.com> | 2016-07-08 11:53:26 +0100 |
|---|---|---|
| committer | Paolo Bonzini <pbonzini@redhat.com> | 2016-08-01 18:42:24 +0200 |
| commit | 2a06dab877dee3d4144c3ba32c662db18a1fdd2b (patch) | |
| tree | 70073a52c9257c1462f9fd9d9a15ca73e68df94d /arch | |
| parent | 0d17aea5c27d7d748b1d8116d275b2b17dc5cad6 (diff) | |
| download | linux-2a06dab877dee3d4144c3ba32c662db18a1fdd2b.tar.bz2 | |
MIPS: KVM: Fail if ebase doesn't fit in CP0_EBase
Fail if the address of the allocated exception base doesn't fit into the
CP0_EBase register. This can happen on MIPS64 if CP0_EBase.WG isn't
implemented but RAM is available outside of the range of KSeg0.
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
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Diffstat (limited to 'arch')
| -rw-r--r-- | arch/mips/kvm/mips.c | 12 |
1 files changed, 12 insertions, 0 deletions
diff --git a/arch/mips/kvm/mips.c b/arch/mips/kvm/mips.c index 414b00074e29..a6ea084b4d9d 100644 --- a/arch/mips/kvm/mips.c +++ b/arch/mips/kvm/mips.c @@ -300,6 +300,18 @@ struct kvm_vcpu *kvm_arch_vcpu_create(struct kvm *kvm, unsigned int id) kvm_debug("Allocated %d bytes for KVM Exception Handlers @ %p\n", ALIGN(size, PAGE_SIZE), gebase); + /* + * Check new ebase actually fits in CP0_EBase. The lack of a write gate + * limits us to the low 512MB of physical address space. If the memory + * we allocate is out of range, just give up now. + */ + if (!cpu_has_ebase_wg && virt_to_phys(gebase) >= 0x20000000) { + kvm_err("CP0_EBase.WG required for guest exception base %pK\n", + gebase); + err = -ENOMEM; + goto out_free_gebase; + } + /* Save new ebase */ vcpu->arch.guest_ebase = gebase; |