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| author | Paul Mackerras <paulus@ozlabs.org> | 2017-10-26 17:00:22 +1100 |
|---|---|---|
| committer | Paul Mackerras <paulus@ozlabs.org> | 2017-11-01 15:09:32 +1100 |
| commit | 00bb6ae5006205e041ce9784c819460562351d47 (patch) | |
| tree | 160bc3ef885ab48be48b15c7d00b4b0a827a1a63 /arch/powerpc | |
| parent | 891f1ebf659edd24bba93182a8de0ba082dcff72 (diff) | |
| download | linux-stable-00bb6ae5006205e041ce9784c819460562351d47.tar.gz linux-stable-00bb6ae5006205e041ce9784c819460562351d47.tar.bz2 linux-stable-00bb6ae5006205e041ce9784c819460562351d47.zip | |
KVM: PPC: Book3S HV: Don't call real-mode XICS hypercall handlers if not enabled
When running a guest on a POWER9 system with the in-kernel XICS
emulation disabled (for example by running QEMU with the parameter
"-machine pseries,kernel_irqchip=off"), the kernel does not pass
the XICS-related hypercalls such as H_CPPR up to userspace for
emulation there as it should.
The reason for this is that the real-mode handlers for these
hypercalls don't check whether a XICS device has been instantiated
before calling the xics-on-xive code. That code doesn't check
either, leading to potential NULL pointer dereferences because
vcpu->arch.xive_vcpu is NULL. Those dereferences won't cause an
exception in real mode but will lead to kernel memory corruption.
This fixes it by adding kvmppc_xics_enabled() checks before calling
the XICS functions.
Cc: stable@vger.kernel.org # v4.11+
Fixes: 5af50993850a ("KVM: PPC: Book3S HV: Native usage of the XIVE interrupt controller")
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
Diffstat (limited to 'arch/powerpc')
| -rw-r--r-- | arch/powerpc/kvm/book3s_hv_builtin.c | 12 |
1 files changed, 12 insertions, 0 deletions
diff --git a/arch/powerpc/kvm/book3s_hv_builtin.c b/arch/powerpc/kvm/book3s_hv_builtin.c index 2791922e97e2..e38cc2df6d2a 100644 --- a/arch/powerpc/kvm/book3s_hv_builtin.c +++ b/arch/powerpc/kvm/book3s_hv_builtin.c @@ -529,6 +529,8 @@ static inline bool is_rm(void) unsigned long kvmppc_rm_h_xirr(struct kvm_vcpu *vcpu) { + if (!kvmppc_xics_enabled(vcpu)) + return H_TOO_HARD; if (xive_enabled()) { if (is_rm()) return xive_rm_h_xirr(vcpu); @@ -541,6 +543,8 @@ unsigned long kvmppc_rm_h_xirr(struct kvm_vcpu *vcpu) unsigned long kvmppc_rm_h_xirr_x(struct kvm_vcpu *vcpu) { + if (!kvmppc_xics_enabled(vcpu)) + return H_TOO_HARD; vcpu->arch.gpr[5] = get_tb(); if (xive_enabled()) { if (is_rm()) @@ -554,6 +558,8 @@ unsigned long kvmppc_rm_h_xirr_x(struct kvm_vcpu *vcpu) unsigned long kvmppc_rm_h_ipoll(struct kvm_vcpu *vcpu, unsigned long server) { + if (!kvmppc_xics_enabled(vcpu)) + return H_TOO_HARD; if (xive_enabled()) { if (is_rm()) return xive_rm_h_ipoll(vcpu, server); @@ -567,6 +573,8 @@ unsigned long kvmppc_rm_h_ipoll(struct kvm_vcpu *vcpu, unsigned long server) int kvmppc_rm_h_ipi(struct kvm_vcpu *vcpu, unsigned long server, unsigned long mfrr) { + if (!kvmppc_xics_enabled(vcpu)) + return H_TOO_HARD; if (xive_enabled()) { if (is_rm()) return xive_rm_h_ipi(vcpu, server, mfrr); @@ -579,6 +587,8 @@ int kvmppc_rm_h_ipi(struct kvm_vcpu *vcpu, unsigned long server, int kvmppc_rm_h_cppr(struct kvm_vcpu *vcpu, unsigned long cppr) { + if (!kvmppc_xics_enabled(vcpu)) + return H_TOO_HARD; if (xive_enabled()) { if (is_rm()) return xive_rm_h_cppr(vcpu, cppr); @@ -591,6 +601,8 @@ int kvmppc_rm_h_cppr(struct kvm_vcpu *vcpu, unsigned long cppr) int kvmppc_rm_h_eoi(struct kvm_vcpu *vcpu, unsigned long xirr) { + if (!kvmppc_xics_enabled(vcpu)) + return H_TOO_HARD; if (xive_enabled()) { if (is_rm()) return xive_rm_h_eoi(vcpu, xirr); |