From acde25726bc6034b628febb8a4c6c0838736ccbf Mon Sep 17 00:00:00 2001 From: Paul Mackerras Date: Wed, 10 May 2017 16:39:41 +1000 Subject: [PATCH 1/3] KVM: PPC: Book3S HV: Add radix checks in real-mode hypercall handlers POWER9 running a radix guest will take some hypervisor interrupts without going to real mode (turning off the MMU). This means that early hypercall handlers may now be called in virtual mode. Most of the handlers work just fine in both modes, but there are some that can crash the host if called in virtual mode, notably the TCE (IOMMU) hypercalls H_PUT_TCE, H_STUFF_TCE and H_PUT_TCE_INDIRECT. These already have both a real-mode and a virtual-mode version, so we arrange for the real-mode version to return H_TOO_HARD for radix guests, which will result in the virtual-mode version being called. The other hypercall which is sensitive to the MMU mode is H_RANDOM. It doesn't have a virtual-mode version, so this adds code to enable it to be called in either mode. An alternative solution was considered which would refuse to call any of the early hypercall handlers when doing a virtual-mode exit from a radix guest. However, the XICS-on-XIVE code depends on the XICS hypercalls being handled early even for virtual-mode exits, because the handlers need to be called before the XIVE vCPU state has been pulled off the hardware. Therefore that solution would have become quite invasive and complicated, and was rejected in favour of the simpler, though less elegant, solution presented here. Reviewed-by: David Gibson Tested-by: David Gibson Signed-off-by: Paul Mackerras --- arch/powerpc/kvm/book3s_64_vio_hv.c | 13 +++++++++++++ arch/powerpc/kvm/book3s_hv_builtin.c | 9 ++++++++- 2 files changed, 21 insertions(+), 1 deletion(-) diff --git a/arch/powerpc/kvm/book3s_64_vio_hv.c b/arch/powerpc/kvm/book3s_64_vio_hv.c index eda0a8f6fae8..3adfd2f5301c 100644 --- a/arch/powerpc/kvm/book3s_64_vio_hv.c +++ b/arch/powerpc/kvm/book3s_64_vio_hv.c @@ -301,6 +301,10 @@ long kvmppc_rm_h_put_tce(struct kvm_vcpu *vcpu, unsigned long liobn, /* udbg_printf("H_PUT_TCE(): liobn=0x%lx ioba=0x%lx, tce=0x%lx\n", */ /* liobn, ioba, tce); */ + /* For radix, we might be in virtual mode, so punt */ + if (kvm_is_radix(vcpu->kvm)) + return H_TOO_HARD; + stt = kvmppc_find_table(vcpu->kvm, liobn); if (!stt) return H_TOO_HARD; @@ -381,6 +385,10 @@ long kvmppc_rm_h_put_tce_indirect(struct kvm_vcpu *vcpu, bool prereg = false; struct kvmppc_spapr_tce_iommu_table *stit; + /* For radix, we might be in virtual mode, so punt */ + if (kvm_is_radix(vcpu->kvm)) + return H_TOO_HARD; + stt = kvmppc_find_table(vcpu->kvm, liobn); if (!stt) return H_TOO_HARD; @@ -491,6 +499,10 @@ long kvmppc_rm_h_stuff_tce(struct kvm_vcpu *vcpu, long i, ret; struct kvmppc_spapr_tce_iommu_table *stit; + /* For radix, we might be in virtual mode, so punt */ + if (kvm_is_radix(vcpu->kvm)) + return H_TOO_HARD; + stt = kvmppc_find_table(vcpu->kvm, liobn); if (!stt) return H_TOO_HARD; @@ -527,6 +539,7 @@ long kvmppc_rm_h_stuff_tce(struct kvm_vcpu *vcpu, return H_SUCCESS; } +/* This can be called in either virtual mode or real mode */ long kvmppc_h_get_tce(struct kvm_vcpu *vcpu, unsigned long liobn, unsigned long ioba) { diff --git a/arch/powerpc/kvm/book3s_hv_builtin.c b/arch/powerpc/kvm/book3s_hv_builtin.c index 88a65923c649..ee4c2558c305 100644 --- a/arch/powerpc/kvm/book3s_hv_builtin.c +++ b/arch/powerpc/kvm/book3s_hv_builtin.c @@ -207,7 +207,14 @@ EXPORT_SYMBOL_GPL(kvmppc_hwrng_present); long kvmppc_h_random(struct kvm_vcpu *vcpu) { - if (powernv_get_random_real_mode(&vcpu->arch.gpr[4])) + int r; + + /* Only need to do the expensive mfmsr() on radix */ + if (kvm_is_radix(vcpu->kvm) && (mfmsr() & MSR_IR)) + r = powernv_get_random_long(&vcpu->arch.gpr[4]); + else + r = powernv_get_random_real_mode(&vcpu->arch.gpr[4]); + if (r) return H_SUCCESS; return H_HARDWARE; From 67325e988faea735d663799b6d152b5f4254093c Mon Sep 17 00:00:00 2001 From: Paul Mackerras Date: Thu, 11 May 2017 11:33:30 +1000 Subject: [PATCH 2/3] KVM: PPC: Book3S PR: Check copy_to/from_user return values MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit The PR KVM implementation of the PAPR HPT hypercalls (H_ENTER etc.) access an image of the HPT in userspace memory using copy_from_user and copy_to_user. Recently, the declarations of those functions were annotated to indicate that the return value must be checked. Since this code doesn't currently check the return value, this causes compile warnings like the ones shown below, and since on PPC the default is to compile arch/powerpc with -Werror, this causes the build to fail. To fix this, we check the return values, and if non-zero, fail the hypercall being processed with a H_FUNCTION error return value. There is really no good error return value to use since PAPR didn't envisage the possibility that the hypervisor may not be able to access the guest's HPT, and H_FUNCTION (function not supported) seems as good as any. The typical compile warnings look like this: CC arch/powerpc/kvm/book3s_pr_papr.o /home/paulus/kernel/kvm/arch/powerpc/kvm/book3s_pr_papr.c: In function ‘kvmppc_h_pr_enter’: /home/paulus/kernel/kvm/arch/powerpc/kvm/book3s_pr_papr.c:53:2: error: ignoring return value of ‘copy_from_user’, declared with attribute warn_unused_result [-Werror=unused-result] copy_from_user(pteg, (void __user *)pteg_addr, sizeof(pteg)); ^ /home/paulus/kernel/kvm/arch/powerpc/kvm/book3s_pr_papr.c:74:2: error: ignoring return value of ‘copy_to_user’, declared with attribute warn_unused_result [-Werror=unused-result] copy_to_user((void __user *)pteg_addr, hpte, HPTE_SIZE); ^ ... etc. Signed-off-by: Paul Mackerras --- arch/powerpc/kvm/book3s_pr_papr.c | 34 +++++++++++++++++++++++-------- 1 file changed, 26 insertions(+), 8 deletions(-) diff --git a/arch/powerpc/kvm/book3s_pr_papr.c b/arch/powerpc/kvm/book3s_pr_papr.c index bcbeeb62dd13..a04384adece7 100644 --- a/arch/powerpc/kvm/book3s_pr_papr.c +++ b/arch/powerpc/kvm/book3s_pr_papr.c @@ -50,7 +50,9 @@ static int kvmppc_h_pr_enter(struct kvm_vcpu *vcpu) pteg_addr = get_pteg_addr(vcpu, pte_index); mutex_lock(&vcpu->kvm->arch.hpt_mutex); - copy_from_user(pteg, (void __user *)pteg_addr, sizeof(pteg)); + ret = H_FUNCTION; + if (copy_from_user(pteg, (void __user *)pteg_addr, sizeof(pteg))) + goto done; hpte = pteg; ret = H_PTEG_FULL; @@ -71,7 +73,9 @@ static int kvmppc_h_pr_enter(struct kvm_vcpu *vcpu) hpte[0] = cpu_to_be64(kvmppc_get_gpr(vcpu, 6)); hpte[1] = cpu_to_be64(kvmppc_get_gpr(vcpu, 7)); pteg_addr += i * HPTE_SIZE; - copy_to_user((void __user *)pteg_addr, hpte, HPTE_SIZE); + ret = H_FUNCTION; + if (copy_to_user((void __user *)pteg_addr, hpte, HPTE_SIZE)) + goto done; kvmppc_set_gpr(vcpu, 4, pte_index | i); ret = H_SUCCESS; @@ -93,7 +97,9 @@ static int kvmppc_h_pr_remove(struct kvm_vcpu *vcpu) pteg = get_pteg_addr(vcpu, pte_index); mutex_lock(&vcpu->kvm->arch.hpt_mutex); - copy_from_user(pte, (void __user *)pteg, sizeof(pte)); + ret = H_FUNCTION; + if (copy_from_user(pte, (void __user *)pteg, sizeof(pte))) + goto done; pte[0] = be64_to_cpu((__force __be64)pte[0]); pte[1] = be64_to_cpu((__force __be64)pte[1]); @@ -103,7 +109,9 @@ static int kvmppc_h_pr_remove(struct kvm_vcpu *vcpu) ((flags & H_ANDCOND) && (pte[0] & avpn) != 0)) goto done; - copy_to_user((void __user *)pteg, &v, sizeof(v)); + ret = H_FUNCTION; + if (copy_to_user((void __user *)pteg, &v, sizeof(v))) + goto done; rb = compute_tlbie_rb(pte[0], pte[1], pte_index); vcpu->arch.mmu.tlbie(vcpu, rb, rb & 1 ? true : false); @@ -171,7 +179,10 @@ static int kvmppc_h_pr_bulk_remove(struct kvm_vcpu *vcpu) } pteg = get_pteg_addr(vcpu, tsh & H_BULK_REMOVE_PTEX); - copy_from_user(pte, (void __user *)pteg, sizeof(pte)); + if (copy_from_user(pte, (void __user *)pteg, sizeof(pte))) { + ret = H_FUNCTION; + break; + } pte[0] = be64_to_cpu((__force __be64)pte[0]); pte[1] = be64_to_cpu((__force __be64)pte[1]); @@ -184,7 +195,10 @@ static int kvmppc_h_pr_bulk_remove(struct kvm_vcpu *vcpu) tsh |= H_BULK_REMOVE_NOT_FOUND; } else { /* Splat the pteg in (userland) hpt */ - copy_to_user((void __user *)pteg, &v, sizeof(v)); + if (copy_to_user((void __user *)pteg, &v, sizeof(v))) { + ret = H_FUNCTION; + break; + } rb = compute_tlbie_rb(pte[0], pte[1], tsh & H_BULK_REMOVE_PTEX); @@ -211,7 +225,9 @@ static int kvmppc_h_pr_protect(struct kvm_vcpu *vcpu) pteg = get_pteg_addr(vcpu, pte_index); mutex_lock(&vcpu->kvm->arch.hpt_mutex); - copy_from_user(pte, (void __user *)pteg, sizeof(pte)); + ret = H_FUNCTION; + if (copy_from_user(pte, (void __user *)pteg, sizeof(pte))) + goto done; pte[0] = be64_to_cpu((__force __be64)pte[0]); pte[1] = be64_to_cpu((__force __be64)pte[1]); @@ -234,7 +250,9 @@ static int kvmppc_h_pr_protect(struct kvm_vcpu *vcpu) vcpu->arch.mmu.tlbie(vcpu, rb, rb & 1 ? true : false); pte[0] = (__force u64)cpu_to_be64(pte[0]); pte[1] = (__force u64)cpu_to_be64(pte[1]); - copy_to_user((void __user *)pteg, pte, sizeof(pte)); + ret = H_FUNCTION; + if (copy_to_user((void __user *)pteg, pte, sizeof(pte))) + goto done; ret = H_SUCCESS; done: From 76d837a4c0f905f98088877d780169d7a14a6b29 Mon Sep 17 00:00:00 2001 From: Paul Mackerras Date: Thu, 11 May 2017 14:31:59 +1000 Subject: [PATCH 3/3] KVM: PPC: Book3S PR: Don't include SPAPR TCE code on non-pseries platforms MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Commit e91aa8e6ecd5 ("KVM: PPC: Enable IOMMU_API for KVM_BOOK3S_64 permanently", 2017-03-22) enabled the SPAPR TCE code for all 64-bit Book 3S kernel configurations in order to simplify the code and reduce #ifdefs. However, 64-bit Book 3S PPC platforms other than pseries and powernv don't implement the necessary IOMMU callbacks, leading to build failures like the following (for a pasemi config): scripts/kconfig/conf --silentoldconfig Kconfig warning: (KVM_BOOK3S_64) selects SPAPR_TCE_IOMMU which has unmet direct dependencies (IOMMU_SUPPORT && (PPC_POWERNV || PPC_PSERIES)) ... CC [M] arch/powerpc/kvm/book3s_64_vio.o /home/paulus/kernel/kvm/arch/powerpc/kvm/book3s_64_vio.c: In function ‘kvmppc_clear_tce’: /home/paulus/kernel/kvm/arch/powerpc/kvm/book3s_64_vio.c:363:2: error: implicit declaration of function ‘iommu_tce_xchg’ [-Werror=implicit-function-declaration] iommu_tce_xchg(tbl, entry, &hpa, &dir); ^ To fix this, we make the inclusion of the SPAPR TCE support, and the code that uses it in book3s_vio.c and book3s_vio_hv.c, depend on the inclusion of support for the pseries and/or powernv platforms. This means that when running a 'pseries' guest on those platforms, the guest won't have in-kernel acceleration of the PAPR TCE hypercalls, but at least now they compile. Reviewed-by: Alexey Kardashevskiy Signed-off-by: Paul Mackerras --- arch/powerpc/kvm/Kconfig | 2 +- arch/powerpc/kvm/Makefile | 4 +-- arch/powerpc/kvm/book3s_pr_papr.c | 46 +++++++++++++++++++++---------- arch/powerpc/kvm/powerpc.c | 4 ++- 4 files changed, 38 insertions(+), 18 deletions(-) diff --git a/arch/powerpc/kvm/Kconfig b/arch/powerpc/kvm/Kconfig index 24de532c1736..0c52cb5d43f5 100644 --- a/arch/powerpc/kvm/Kconfig +++ b/arch/powerpc/kvm/Kconfig @@ -67,7 +67,7 @@ config KVM_BOOK3S_64 select KVM_BOOK3S_64_HANDLER select KVM select KVM_BOOK3S_PR_POSSIBLE if !KVM_BOOK3S_HV_POSSIBLE - select SPAPR_TCE_IOMMU if IOMMU_SUPPORT + select SPAPR_TCE_IOMMU if IOMMU_SUPPORT && (PPC_SERIES || PPC_POWERNV) ---help--- Support running unmodified book3s_64 and book3s_32 guest kernels in virtual machines on book3s_64 host processors. diff --git a/arch/powerpc/kvm/Makefile b/arch/powerpc/kvm/Makefile index d91a2604c496..381a6ec0ff3b 100644 --- a/arch/powerpc/kvm/Makefile +++ b/arch/powerpc/kvm/Makefile @@ -46,7 +46,7 @@ kvm-e500mc-objs := \ e500_emulate.o kvm-objs-$(CONFIG_KVM_E500MC) := $(kvm-e500mc-objs) -kvm-book3s_64-builtin-objs-$(CONFIG_KVM_BOOK3S_64_HANDLER) := \ +kvm-book3s_64-builtin-objs-$(CONFIG_SPAPR_TCE_IOMMU) := \ book3s_64_vio_hv.o kvm-pr-y := \ @@ -90,11 +90,11 @@ kvm-book3s_64-objs-$(CONFIG_KVM_XICS) += \ book3s_xics.o kvm-book3s_64-objs-$(CONFIG_KVM_XIVE) += book3s_xive.o +kvm-book3s_64-objs-$(CONFIG_SPAPR_TCE_IOMMU) += book3s_64_vio.o kvm-book3s_64-module-objs := \ $(common-objs-y) \ book3s.o \ - book3s_64_vio.o \ book3s_rtas.o \ $(kvm-book3s_64-objs-y) diff --git a/arch/powerpc/kvm/book3s_pr_papr.c b/arch/powerpc/kvm/book3s_pr_papr.c index a04384adece7..8a4205fa774f 100644 --- a/arch/powerpc/kvm/book3s_pr_papr.c +++ b/arch/powerpc/kvm/book3s_pr_papr.c @@ -262,20 +262,6 @@ static int kvmppc_h_pr_protect(struct kvm_vcpu *vcpu) return EMULATE_DONE; } -static int kvmppc_h_pr_put_tce(struct kvm_vcpu *vcpu) -{ - unsigned long liobn = kvmppc_get_gpr(vcpu, 4); - unsigned long ioba = kvmppc_get_gpr(vcpu, 5); - unsigned long tce = kvmppc_get_gpr(vcpu, 6); - long rc; - - rc = kvmppc_h_put_tce(vcpu, liobn, ioba, tce); - if (rc == H_TOO_HARD) - return EMULATE_FAIL; - kvmppc_set_gpr(vcpu, 3, rc); - return EMULATE_DONE; -} - static int kvmppc_h_pr_logical_ci_load(struct kvm_vcpu *vcpu) { long rc; @@ -298,6 +284,21 @@ static int kvmppc_h_pr_logical_ci_store(struct kvm_vcpu *vcpu) return EMULATE_DONE; } +#ifdef CONFIG_SPAPR_TCE_IOMMU +static int kvmppc_h_pr_put_tce(struct kvm_vcpu *vcpu) +{ + unsigned long liobn = kvmppc_get_gpr(vcpu, 4); + unsigned long ioba = kvmppc_get_gpr(vcpu, 5); + unsigned long tce = kvmppc_get_gpr(vcpu, 6); + long rc; + + rc = kvmppc_h_put_tce(vcpu, liobn, ioba, tce); + if (rc == H_TOO_HARD) + return EMULATE_FAIL; + kvmppc_set_gpr(vcpu, 3, rc); + return EMULATE_DONE; +} + static int kvmppc_h_pr_put_tce_indirect(struct kvm_vcpu *vcpu) { unsigned long liobn = kvmppc_get_gpr(vcpu, 4); @@ -329,6 +330,23 @@ static int kvmppc_h_pr_stuff_tce(struct kvm_vcpu *vcpu) return EMULATE_DONE; } +#else /* CONFIG_SPAPR_TCE_IOMMU */ +static int kvmppc_h_pr_put_tce(struct kvm_vcpu *vcpu) +{ + return EMULATE_FAIL; +} + +static int kvmppc_h_pr_put_tce_indirect(struct kvm_vcpu *vcpu) +{ + return EMULATE_FAIL; +} + +static int kvmppc_h_pr_stuff_tce(struct kvm_vcpu *vcpu) +{ + return EMULATE_FAIL; +} +#endif /* CONFIG_SPAPR_TCE_IOMMU */ + static int kvmppc_h_pr_xics_hcall(struct kvm_vcpu *vcpu, u32 cmd) { long rc = kvmppc_xics_hcall(vcpu, cmd); diff --git a/arch/powerpc/kvm/powerpc.c b/arch/powerpc/kvm/powerpc.c index f7cf2cd564ef..7f71ab5fcad1 100644 --- a/arch/powerpc/kvm/powerpc.c +++ b/arch/powerpc/kvm/powerpc.c @@ -1749,7 +1749,7 @@ long kvm_arch_vm_ioctl(struct file *filp, r = kvm_vm_ioctl_enable_cap(kvm, &cap); break; } -#ifdef CONFIG_PPC_BOOK3S_64 +#ifdef CONFIG_SPAPR_TCE_IOMMU case KVM_CREATE_SPAPR_TCE_64: { struct kvm_create_spapr_tce_64 create_tce_64; @@ -1780,6 +1780,8 @@ long kvm_arch_vm_ioctl(struct file *filp, r = kvm_vm_ioctl_create_spapr_tce(kvm, &create_tce_64); goto out; } +#endif +#ifdef CONFIG_PPC_BOOK3S_64 case KVM_PPC_GET_SMMU_INFO: { struct kvm_ppc_smmu_info info; struct kvm *kvm = filp->private_data;