diff options
| -rw-r--r-- | Documentation/virtual/kvm/ppc-pv.txt | 14 | ||||
| -rw-r--r-- | arch/powerpc/include/asm/kvm_host.h | 1 | ||||
| -rw-r--r-- | arch/powerpc/include/uapi/asm/kvm_para.h | 6 | ||||
| -rw-r--r-- | arch/powerpc/kvm/book3s_64_mmu.c | 3 | ||||
| -rw-r--r-- | arch/powerpc/kvm/powerpc.c | 14 |
5 files changed, 36 insertions, 2 deletions
diff --git a/Documentation/virtual/kvm/ppc-pv.txt b/Documentation/virtual/kvm/ppc-pv.txt index 4643cde517c..319560646f3 100644 --- a/Documentation/virtual/kvm/ppc-pv.txt +++ b/Documentation/virtual/kvm/ppc-pv.txt @@ -94,10 +94,24 @@ a bitmap of available features inside the magic page. The following enhancements to the magic page are currently available: KVM_MAGIC_FEAT_SR Maps SR registers r/w in the magic page + KVM_MAGIC_FEAT_MAS0_TO_SPRG7 Maps MASn, ESR, PIR and high SPRGs For enhanced features in the magic page, please check for the existence of the feature before using them! +Magic page flags +================ + +In addition to features that indicate whether a host is capable of a particular +feature we also have a channel for a guest to tell the guest whether it's capable +of something. This is what we call "flags". + +Flags are passed to the host in the low 12 bits of the Effective Address. + +The following flags are currently available for a guest to expose: + + MAGIC_PAGE_FLAG_NOT_MAPPED_NX Guest handles NX bits correclty wrt magic page + MSR bits ======== diff --git a/arch/powerpc/include/asm/kvm_host.h b/arch/powerpc/include/asm/kvm_host.h index 29fbb554af5..bb66d8b8efd 100644 --- a/arch/powerpc/include/asm/kvm_host.h +++ b/arch/powerpc/include/asm/kvm_host.h @@ -631,6 +631,7 @@ struct kvm_vcpu_arch { #endif unsigned long magic_page_pa; /* phys addr to map the magic page to */ unsigned long magic_page_ea; /* effect. addr to map the magic page to */ + bool disable_kernel_nx; int irq_type; /* one of KVM_IRQ_* */ int irq_cpu_id; diff --git a/arch/powerpc/include/uapi/asm/kvm_para.h b/arch/powerpc/include/uapi/asm/kvm_para.h index e3af3286a06..91e42f09b32 100644 --- a/arch/powerpc/include/uapi/asm/kvm_para.h +++ b/arch/powerpc/include/uapi/asm/kvm_para.h @@ -82,10 +82,16 @@ struct kvm_vcpu_arch_shared { #define KVM_FEATURE_MAGIC_PAGE 1 +/* Magic page flags from host to guest */ + #define KVM_MAGIC_FEAT_SR (1 << 0) /* MASn, ESR, PIR, and high SPRGs */ #define KVM_MAGIC_FEAT_MAS0_TO_SPRG7 (1 << 1) +/* Magic page flags from guest to host */ + +#define MAGIC_PAGE_FLAG_NOT_MAPPED_NX (1 << 0) + #endif /* _UAPI__POWERPC_KVM_PARA_H__ */ diff --git a/arch/powerpc/kvm/book3s_64_mmu.c b/arch/powerpc/kvm/book3s_64_mmu.c index 278729f4df8..774a253ca4e 100644 --- a/arch/powerpc/kvm/book3s_64_mmu.c +++ b/arch/powerpc/kvm/book3s_64_mmu.c @@ -313,6 +313,9 @@ do_second: gpte->raddr = (r & HPTE_R_RPN & ~eaddr_mask) | (eaddr & eaddr_mask); gpte->page_size = pgsize; gpte->may_execute = ((r & HPTE_R_N) ? false : true); + if (unlikely(vcpu->arch.disable_kernel_nx) && + !(kvmppc_get_msr(vcpu) & MSR_PR)) + gpte->may_execute = true; gpte->may_read = false; gpte->may_write = false; diff --git a/arch/powerpc/kvm/powerpc.c b/arch/powerpc/kvm/powerpc.c index b4e15bf3ff8..154f352c39a 100644 --- a/arch/powerpc/kvm/powerpc.c +++ b/arch/powerpc/kvm/powerpc.c @@ -177,8 +177,18 @@ int kvmppc_kvm_pv(struct kvm_vcpu *vcpu) vcpu->arch.shared_big_endian = shared_big_endian; #endif - vcpu->arch.magic_page_pa = param1; - vcpu->arch.magic_page_ea = param2; + if (!(param2 & MAGIC_PAGE_FLAG_NOT_MAPPED_NX)) { + /* + * Older versions of the Linux magic page code had + * a bug where they would map their trampoline code + * NX. If that's the case, remove !PR NX capability. + */ + vcpu->arch.disable_kernel_nx = true; + kvm_make_request(KVM_REQ_TLB_FLUSH, vcpu); + } + + vcpu->arch.magic_page_pa = param1 & ~0xfffULL; + vcpu->arch.magic_page_ea = param2 & ~0xfffULL; r2 = KVM_MAGIC_FEAT_SR | KVM_MAGIC_FEAT_MAS0_TO_SPRG7; |