From: Alexander Graf <agraf@suse.de> To: kvm-ppc@vger.kernel.org Cc: kvm@vger.kernel.org, pbonzini@redhat.com, mtosatti@redhat.com Subject: [PULL 24/41] KVM: PPC: Disable NX for old magic page using guests Date: Fri, 30 May 2014 14:42:39 +0200 [thread overview] Message-ID: <1401453776-55285-25-git-send-email-agraf@suse.de> (raw) In-Reply-To: <1401453776-55285-1-git-send-email-agraf@suse.de> Old guests try to use the magic page, but map their trampoline code inside of an NX region. Since we can't fix those old kernels, try to detect whether the guest is sane or not. If not, just disable NX functionality in KVM so that old guests at least work at all. For newer guests, add a bit that we can set to keep NX functionality available. Signed-off-by: Alexander Graf <agraf@suse.de> --- Documentation/virtual/kvm/ppc-pv.txt | 14 ++++++++++++++ arch/powerpc/include/asm/kvm_host.h | 1 + arch/powerpc/include/uapi/asm/kvm_para.h | 6 ++++++ arch/powerpc/kvm/book3s_64_mmu.c | 3 +++ 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 4643cde..3195606 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 29fbb55..bb66d8b 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 e3af328..91e42f0 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 278729f..774a253 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 b4e15bf..154f352 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; -- 1.8.1.4
WARNING: multiple messages have this Message-ID (diff)
From: Alexander Graf <agraf@suse.de> To: kvm-ppc@vger.kernel.org Cc: kvm@vger.kernel.org, pbonzini@redhat.com, mtosatti@redhat.com Subject: [PULL 24/41] KVM: PPC: Disable NX for old magic page using guests Date: Fri, 30 May 2014 12:42:39 +0000 [thread overview] Message-ID: <1401453776-55285-25-git-send-email-agraf@suse.de> (raw) In-Reply-To: <1401453776-55285-1-git-send-email-agraf@suse.de> Old guests try to use the magic page, but map their trampoline code inside of an NX region. Since we can't fix those old kernels, try to detect whether the guest is sane or not. If not, just disable NX functionality in KVM so that old guests at least work at all. For newer guests, add a bit that we can set to keep NX functionality available. Signed-off-by: Alexander Graf <agraf@suse.de> --- Documentation/virtual/kvm/ppc-pv.txt | 14 ++++++++++++++ arch/powerpc/include/asm/kvm_host.h | 1 + arch/powerpc/include/uapi/asm/kvm_para.h | 6 ++++++ arch/powerpc/kvm/book3s_64_mmu.c | 3 +++ 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 4643cde..3195606 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 29fbb55..bb66d8b 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 e3af328..91e42f0 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 278729f..774a253 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 b4e15bf..154f352 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; -- 1.8.1.4
next prev parent reply other threads:[~2014-05-30 12:43 UTC|newest] Thread overview: 104+ messages / expand[flat|nested] mbox.gz Atom feed top 2014-05-30 12:42 [PULL 00/41] ppc patch queue 2014-05-30 Alexander Graf 2014-05-30 12:42 ` Alexander Graf 2014-05-30 12:42 ` [PULL 01/41] KVM: PPC: E500: Ignore L1CSR1_ICFI,ICLFR Alexander Graf 2014-05-30 12:42 ` Alexander Graf 2014-05-30 12:42 ` [PULL 02/41] KVM: PPC: E500: Add dcbtls emulation Alexander Graf 2014-05-30 12:42 ` Alexander Graf 2014-05-30 12:42 ` [PULL 03/41] KVM: PPC: BOOK3S: PR: Enable Little Endian PR guest Alexander Graf 2014-05-30 12:42 ` Alexander Graf 2014-05-30 12:42 ` [PULL 04/41] KVM: PPC: BOOK3S: PR: Fix WARN_ON with debug options on Alexander Graf 2014-05-30 12:42 ` Alexander Graf 2014-05-30 12:42 ` [PULL 05/41] KVM: PPC: Book3S: PR: Fix C/R bit setting Alexander Graf 2014-05-30 12:42 ` Alexander Graf 2014-05-30 12:42 ` [PULL 06/41] KVM: PPC: Book3S_32: PR: Access HTAB in big endian Alexander Graf 2014-05-30 12:42 ` Alexander Graf 2014-05-30 12:42 ` [PULL 07/41] KVM: PPC: Book3S_64 " Alexander Graf 2014-05-30 12:42 ` Alexander Graf 2014-05-30 12:42 ` [PULL 08/41] KVM: PPC: Book3S_64 PR: Access shadow slb " Alexander Graf 2014-05-30 12:42 ` Alexander Graf 2014-05-30 12:42 ` [PULL 09/41] KVM: PPC: Book3S PR: Default to big endian guest Alexander Graf 2014-05-30 12:42 ` Alexander Graf 2014-05-30 12:42 ` [PULL 10/41] KVM: PPC: Book3S PR: PAPR: Access HTAB in big endian Alexander Graf 2014-05-30 12:42 ` Alexander Graf 2014-05-30 12:42 ` [PULL 11/41] KVM: PPC: Book3S PR: PAPR: Access RTAS " Alexander Graf 2014-05-30 12:42 ` Alexander Graf 2014-05-30 12:42 ` [PULL 12/41] KVM: PPC: PR: Fill pvinfo hcall instructions " Alexander Graf 2014-05-30 12:42 ` Alexander Graf 2014-05-30 12:42 ` [PULL 13/41] KVM: PPC: Make shared struct aka magic page guest endian Alexander Graf 2014-05-30 12:42 ` Alexander Graf 2014-05-30 12:42 ` [PULL 14/41] KVM: PPC: Book3S PR: Do dcbz32 patching with big endian instructions Alexander Graf 2014-05-30 12:42 ` Alexander Graf 2014-05-30 12:42 ` [PULL 15/41] KVM: PPC: Book3S: Move little endian conflict to HV KVM Alexander Graf 2014-05-30 12:42 ` Alexander Graf 2014-05-30 12:42 ` [PULL 16/41] KVM: PPC: Book3S PR: Ignore PMU SPRs Alexander Graf 2014-05-30 12:42 ` Alexander Graf 2014-05-30 12:42 ` [PULL 17/41] KVM: PPC: Book3S PR: Emulate TIR register Alexander Graf 2014-05-30 12:42 ` Alexander Graf 2014-05-30 12:42 ` [PULL 18/41] KVM: PPC: Book3S PR: Handle Facility interrupt and FSCR Alexander Graf 2014-05-30 12:42 ` Alexander Graf 2014-05-30 12:42 ` [PULL 19/41] KVM: PPC: Book3S PR: Expose TAR facility to guest Alexander Graf 2014-05-30 12:42 ` Alexander Graf 2014-05-30 12:42 ` [PULL 20/41] KVM: PPC: Book3S PR: Expose EBB registers Alexander Graf 2014-05-30 12:42 ` Alexander Graf 2014-05-30 12:42 ` [PULL 21/41] KVM: PPC: Book3S PR: Expose TM registers Alexander Graf 2014-05-30 12:42 ` Alexander Graf 2014-05-30 12:42 ` [PULL 22/41] KVM: PPC: BOOK3S: HV: Prefer CMA region for hash page table allocation Alexander Graf 2014-05-30 12:42 ` Alexander Graf 2014-05-30 12:42 ` [PULL 23/41] KVM: PPC: BOOK3S: HV: Add mixed page-size support for guest Alexander Graf 2014-05-30 12:42 ` Alexander Graf 2014-05-30 12:42 ` Alexander Graf [this message] 2014-05-30 12:42 ` [PULL 24/41] KVM: PPC: Disable NX for old magic page using guests Alexander Graf 2014-05-30 12:42 ` [PULL 25/41] PPC: KVM: Make NX bit available with magic page Alexander Graf 2014-05-30 12:42 ` Alexander Graf 2014-05-30 12:42 ` [PULL 26/41] KVM: PPC: BOOK3S: Always use the saved DAR value Alexander Graf 2014-05-30 12:42 ` Alexander Graf 2014-05-30 12:42 ` [PULL 27/41] KVM: PPC: BOOK3S: Remove open coded make_dsisr in alignment handler Alexander Graf 2014-05-30 12:42 ` Alexander Graf 2014-05-30 12:42 ` [PULL 28/41] PPC: ePAPR: Fix hypercall on LE guest Alexander Graf 2014-05-30 12:42 ` Alexander Graf 2014-05-30 12:42 ` [PULL 29/41] KVM: PPC: Graciously fail broken LE hypercalls Alexander Graf 2014-05-30 12:42 ` Alexander Graf 2014-05-30 12:42 ` [PULL 30/41] KVM: PPC: MPIC: Reset IRQ source private members Alexander Graf 2014-05-30 12:42 ` Alexander Graf 2014-05-30 12:42 ` [PULL 31/41] KVM: PPC: Add CAP to indicate hcall fixes Alexander Graf 2014-05-30 12:42 ` Alexander Graf 2014-05-30 12:42 ` [PULL 32/41] KVM: PPC: Book3S: Add ONE_REG register names that were missed Alexander Graf 2014-05-30 12:42 ` Alexander Graf 2014-05-30 12:42 ` [PULL 33/41] KVM: PPC: Book3S: Move KVM_REG_PPC_WORT to an unused register number Alexander Graf 2014-05-30 12:42 ` Alexander Graf 2014-05-30 15:50 ` Paolo Bonzini 2014-05-30 15:50 ` Paolo Bonzini 2014-05-30 15:53 ` Alexander Graf 2014-05-30 15:53 ` Alexander Graf 2014-05-30 15:55 ` Paolo Bonzini 2014-05-30 15:55 ` Paolo Bonzini 2014-05-30 15:58 ` Alexander Graf 2014-05-30 15:58 ` Alexander Graf 2014-05-30 16:03 ` Paolo Bonzini 2014-05-30 16:03 ` Paolo Bonzini 2014-05-30 16:08 ` Alexander Graf 2014-05-30 16:08 ` Alexander Graf 2014-05-30 16:11 ` Paolo Bonzini 2014-05-30 16:11 ` Paolo Bonzini 2014-05-30 16:14 ` Alexander Graf 2014-05-30 16:14 ` Alexander Graf 2014-05-30 12:42 ` [PULL 34/41] KVM: PPC: Book3S HV: Fix check for running inside guest in global_invalidates() Alexander Graf 2014-05-30 12:42 ` Alexander Graf 2014-05-30 12:42 ` [PULL 35/41] KVM: PPC: Book3S HV: Put huge-page HPTEs in rmap chain for base address Alexander Graf 2014-05-30 12:42 ` Alexander Graf 2014-05-30 12:42 ` [PULL 36/41] KVM: PPC: Book3S HV: Fix dirty map for hugepages Alexander Graf 2014-05-30 12:42 ` Alexander Graf 2014-05-30 12:42 ` [PULL 37/41] KVM: PPC: Book3S HV: Make sure we don't miss dirty pages Alexander Graf 2014-05-30 12:42 ` Alexander Graf 2014-05-30 12:42 ` [PULL 38/41] KVM: PPC: Book3S HV: Work around POWER8 performance monitor bugs Alexander Graf 2014-05-30 12:42 ` Alexander Graf 2014-05-30 12:42 ` [PULL 39/41] KVM: PPC: Book3S HV: Fix machine check delivery to guest Alexander Graf 2014-05-30 12:42 ` Alexander Graf 2014-05-30 12:42 ` [PULL 40/41] KVM: PPC: Book3S PR: Use SLB entry 0 Alexander Graf 2014-05-30 12:42 ` Alexander Graf 2014-05-30 12:42 ` [PULL 41/41] KVM: PPC: Book3S PR: Rework SLB switching code Alexander Graf 2014-05-30 12:42 ` Alexander Graf 2014-05-30 12:58 ` [PULL 00/41] ppc patch queue 2014-05-30 Paolo Bonzini 2014-05-30 12:58 ` Paolo Bonzini 2014-05-30 13:10 ` Alexander Graf 2014-05-30 13:10 ` Alexander Graf
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