From mboxrd@z Thu Jan 1 00:00:00 1970 From: Paul Mackerras Subject: Re: [PATCH] KVM: PPC: Book3S: Provide information about hardware/firmware CVE workarounds Date: Wed, 17 Jan 2018 08:51:00 +1100 Message-ID: <20180116215100.GB15196@fergus.ozlabs.ibm.com> References: <20180116005906.GA5434@fergus.ozlabs.ibm.com> <67f22a14-7192-bc55-b2ed-dfb2f3c33e03@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: kvm@vger.kernel.org, kvm-ppc@vger.kernel.org, David Gibson , Radim =?utf-8?B?S3LEjW3DocWZ?= To: Paolo Bonzini Return-path: Received: from ozlabs.org ([103.22.144.67]:43333 "EHLO ozlabs.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750750AbeAPVvW (ORCPT ); Tue, 16 Jan 2018 16:51:22 -0500 Content-Disposition: inline In-Reply-To: <67f22a14-7192-bc55-b2ed-dfb2f3c33e03@redhat.com> Sender: kvm-owner@vger.kernel.org List-ID: On Tue, Jan 16, 2018 at 03:45:11PM +0100, Paolo Bonzini wrote: > On 16/01/2018 01:59, Paul Mackerras wrote: > > This adds a new ioctl, KVM_PPC_GET_CPU_CHAR, that gives userspace > > information about the underlying machine's level of vulnerability > > to the recently announced vulnerabilities CVE-2017-5715, > > CVE-2017-5753 and CVE-2017-5754, and whether the machine provides > > instructions to assist software to work around the vulnerabilities. > > > > The ioctl returns two u64 words describing characteristics of the > > CPU and required software behaviour respectively, plus two mask > > words which indicate which bits have been filled in by the kernel, > > for extensibility. The bit definitions are the same as for the > > new H_GET_CPU_CHARACTERISTICS hypercall. > > > > There is also a new capability, KVM_CAP_PPC_GET_CPU_CHAR, which > > indicates whether the new ioctl is available. > > > > Signed-off-by: Paul Mackerras > > --- > > Documentation/virtual/kvm/api.txt | 46 +++++++++++++ > > arch/powerpc/include/uapi/asm/kvm.h | 22 +++++++ > > arch/powerpc/kvm/powerpc.c | 124 ++++++++++++++++++++++++++++++++++++ > > include/uapi/linux/kvm.h | 3 + > > 4 files changed, 195 insertions(+) > > > > diff --git a/Documentation/virtual/kvm/api.txt b/Documentation/virtual/kvm/api.txt > > index f670e4b..85ca84a 100644 > > --- a/Documentation/virtual/kvm/api.txt > > +++ b/Documentation/virtual/kvm/api.txt > > @@ -3394,6 +3394,52 @@ invalid, if invalid pages are written to (e.g. after the end of memory) > > or if no page table is present for the addresses (e.g. when using > > hugepages). > > > > +4.108 KVM_PPC_GET_CPU_CHAR > > + > > +Capability: KVM_CAP_PPC_GET_CPU_CHAR > > +Architectures: powerpc > > +Type: vm ioctl > > +Parameters: struct kvm_ppc_cpu_char (out) > > +Returns: 0 on successful completion > > + -EFAULT if struct kvm_ppc_cpu_char cannot be written > > + > > +This ioctl gives userspace information about certain characteristics > > +of the CPU relating to speculative execution of instructions and > > +possible information leakage resulting from speculative execution (see > > +CVE-2017-5715, CVE-2017-5753 and CVE-2017-5754). The information is > > +returned in struct kvm_ppc_cpu_char, which looks like this: > > + > > +struct kvm_ppc_cpu_char { > > + __u64 character; /* characteristics of the CPU */ > > + __u64 behaviour; /* recommended software behaviour */ > > + __u64 character_mask; /* valid bits in character */ > > + __u64 behaviour_mask; /* valid bits in behaviour */ > > +}; > > + > > +For extensibility, the character_mask and behaviour_mask fields > > +indicate which bits of character and behaviour have been filled in by > > +the kernel. If the set of defined bits is extended in future then > > +userspace will be able to tell whether it is running on a kernel that > > +knows about the new bits. > > + > > +The character field describes attributes of the CPU which can help > > +with preventing inadvertent information disclosure - specifically, > > +whether there is an instruction to flash-invalidate the L1 data cache > > +(ori 30,30,0 or mtspr SPRN_TRIG2,rN), whether the L1 data cache is set > > +to a mode where entries can only be used by the thread that created > > +them, whether the bcctr[l] instruction prevents speculation, and > > +whether a speculation barrier instruction (ori 31,31,0) is provided. > > + > > +The behaviour field describes actions that software should take to > > +prevent inadvertent information disclosure, and thus describes which > > +vulnerabilities the hardware is subject to; specifically whether the > > +L1 data cache should be flushed when returning to user mode from the > > +kernel, and whether a speculation barrier should be placed between an > > +array bounds check and the array access. > > + > > +These fields use the same bit definitions as the new > > +H_GET_CPU_CHARACTERISTICS hypercall. > > + > > 5. The kvm_run structure > > ------------------------ > > > > diff --git a/arch/powerpc/include/uapi/asm/kvm.h b/arch/powerpc/include/uapi/asm/kvm.h > > index 61d6049..ce74bed 100644 > > --- a/arch/powerpc/include/uapi/asm/kvm.h > > +++ b/arch/powerpc/include/uapi/asm/kvm.h > > @@ -443,6 +443,28 @@ struct kvm_ppc_rmmu_info { > > __u32 ap_encodings[8]; > > }; > > > > +/* For KVM_PPC_GET_CPU_CHAR */ > > +struct kvm_ppc_cpu_char { > > + __u64 character; /* characteristics of the CPU */ > > + __u64 behaviour; /* recommended software behaviour */ > > + __u64 character_mask; /* valid bits in character */ > > + __u64 behaviour_mask; /* valid bits in behaviour */ > > +}; > > + > > +/* > > + * Values for character and character_mask. > > + * These are identical to the values used by H_GET_CPU_CHARACTERISTICS. > > + */ > > +#define KVM_PPC_CPU_CHAR_SPEC_BAR_ORI31 (1ULL << 63) > > +#define KVM_PPC_CPU_CHAR_BCCTRL_SERIALISED (1ULL << 62) > > +#define KVM_PPC_CPU_CHAR_L1D_FLUSH_ORI30 (1ULL << 61) > > +#define KVM_PPC_CPU_CHAR_L1D_FLUSH_TRIG2 (1ULL << 60) > > +#define KVM_PPC_CPU_CHAR_L1D_THREAD_PRIV (1ULL << 59) > > + > > +#define KVM_PPC_CPU_BEHAV_FAVOUR_SECURITY (1ULL << 63) > > +#define KVM_PPC_CPU_BEHAV_L1D_FLUSH_PR (1ULL << 62) > > +#define KVM_PPC_CPU_BEHAV_BNDS_CHK_SPEC_BAR (1ULL << 61) > > + > > /* Per-vcpu XICS interrupt controller state */ > > #define KVM_REG_PPC_ICP_STATE (KVM_REG_PPC | KVM_REG_SIZE_U64 | 0x8c) > > > > diff --git a/arch/powerpc/kvm/powerpc.c b/arch/powerpc/kvm/powerpc.c > > index 1915e86..c9cecff 100644 > > --- a/arch/powerpc/kvm/powerpc.c > > +++ b/arch/powerpc/kvm/powerpc.c > > @@ -39,6 +39,10 @@ > > #include > > #include > > #include > > +#ifdef CONFIG_PPC_PSERIES > > +#include > > +#include > > +#endif > > > > #include "timing.h" > > #include "irq.h" > > @@ -548,6 +552,7 @@ int kvm_vm_ioctl_check_extension(struct kvm *kvm, long ext) > > #ifdef CONFIG_KVM_XICS > > case KVM_CAP_IRQ_XICS: > > #endif > > + case KVM_CAP_PPC_GET_CPU_CHAR: > > r = 1; > > break; > > > > @@ -1759,6 +1764,117 @@ static int kvm_vm_ioctl_enable_cap(struct kvm *kvm, > > return r; > > } > > > > +#ifdef CONFIG_PPC_BOOK3S_64 > > +/* > > + * These functions check whether the underlying hardware is safe > > + * against attacks based on observing the effects of speculatively > > + * executed instructions, and whether it supplies instructions for > > + * use in workarounds. The information comes from firmware, either > > + * via the device tree on powernv platforms or from an hcall on > > + * pseries platforms. > > + */ > > +#ifdef CONFIG_PPC_PSERIES > > +static int pseries_get_cpu_char(struct kvm_ppc_cpu_char *cp) > > +{ > > + struct h_cpu_char_result c; > > + unsigned long rc; > > + > > + if (!machine_is(pseries)) > > + return -ENOTTY; > > + > > + rc = plpar_get_cpu_characteristics(&c); > > + if (rc == H_SUCCESS) { > > + cp->character = c.character; > > + cp->behaviour = c.behaviour; > > + cp->character_mask = KVM_PPC_CPU_CHAR_SPEC_BAR_ORI31 | > > + KVM_PPC_CPU_CHAR_BCCTRL_SERIALISED | > > + KVM_PPC_CPU_CHAR_L1D_FLUSH_ORI30 | > > + KVM_PPC_CPU_CHAR_L1D_FLUSH_TRIG2 | > > + KVM_PPC_CPU_CHAR_L1D_THREAD_PRIV; > > + cp->behaviour_mask = KVM_PPC_CPU_BEHAV_FAVOUR_SECURITY | > > + KVM_PPC_CPU_BEHAV_L1D_FLUSH_PR | > > + KVM_PPC_CPU_BEHAV_BNDS_CHK_SPEC_BAR; > > + } > > + return 0; > > +} > > +#else > > +static int pseries_get_cpu_char(struct kvm_ppc_cpu_char *cp) > > +{ > > + return -ENOTTY; > > +} > > +#endif > > + > > +static inline bool have_fw_feat(struct device_node *fw_features, > > + const char *state, const char *name) > > +{ > > + struct device_node *np; > > + bool r = false; > > + > > + np = of_get_child_by_name(fw_features, name); > > + if (np) { > > + r = of_property_read_bool(np, state); > > + of_node_put(np); > > + } > > + return r; > > +} > > + > > +static int kvmppc_get_cpu_char(struct kvm_ppc_cpu_char *cp) > > +{ > > + struct device_node *np, *fw_features; > > + int r; > > + > > + memset(cp, 0, sizeof(*cp)); > > + r = pseries_get_cpu_char(cp); > > + if (r != -ENOTTY) > > + return r; > > + > > + np = of_find_node_by_name(NULL, "ibm,opal"); > > + if (np) { > > + fw_features = of_get_child_by_name(np, "fw-features"); > > + of_node_put(np); > > + if (!fw_features) > > + return 0; > > + if (have_fw_feat(fw_features, "enabled", > > + "inst-spec-barrier-ori31,31,0")) > > + cp->character |= KVM_PPC_CPU_CHAR_SPEC_BAR_ORI31; > > + if (have_fw_feat(fw_features, "enabled", > > + "fw-bcctrl-serialized")) > > + cp->character |= KVM_PPC_CPU_CHAR_BCCTRL_SERIALISED; > > + if (have_fw_feat(fw_features, "enabled", > > + "inst-l1d-flush-ori30,30,0")) > > + cp->character |= KVM_PPC_CPU_CHAR_L1D_FLUSH_ORI30; > > + if (have_fw_feat(fw_features, "enabled", > > + "inst-l1d-flush-trig2")) > > + cp->character |= KVM_PPC_CPU_CHAR_L1D_FLUSH_TRIG2; > > + if (have_fw_feat(fw_features, "enabled", > > + "fw-l1d-thread-split")) > > + cp->character |= KVM_PPC_CPU_CHAR_L1D_THREAD_PRIV; > > + cp->character_mask = KVM_PPC_CPU_CHAR_SPEC_BAR_ORI31 | > > + KVM_PPC_CPU_CHAR_BCCTRL_SERIALISED | > > + KVM_PPC_CPU_CHAR_L1D_FLUSH_ORI30 | > > + KVM_PPC_CPU_CHAR_L1D_FLUSH_TRIG2 | > > + KVM_PPC_CPU_CHAR_L1D_THREAD_PRIV; > > + > > + if (have_fw_feat(fw_features, "enabled", > > + "speculation-policy-favor-security")) > > + cp->behaviour |= KVM_PPC_CPU_BEHAV_FAVOUR_SECURITY; > > + if (!have_fw_feat(fw_features, "disabled", > > + "needs-l1d-flush-msr-pr-0-to-1")) > > + cp->behaviour |= KVM_PPC_CPU_BEHAV_L1D_FLUSH_PR; > > + if (!have_fw_feat(fw_features, "disabled", > > + "needs-spec-barrier-for-bound-checks")) > > + cp->behaviour |= KVM_PPC_CPU_BEHAV_BNDS_CHK_SPEC_BAR; > > + cp->behaviour_mask = KVM_PPC_CPU_BEHAV_FAVOUR_SECURITY | > > + KVM_PPC_CPU_BEHAV_L1D_FLUSH_PR | > > + KVM_PPC_CPU_BEHAV_BNDS_CHK_SPEC_BAR; > > + > > + of_node_put(fw_features); > > + } > > + > > + return 0; > > +} > > +#endif > > + > > long kvm_arch_vm_ioctl(struct file *filp, > > unsigned int ioctl, unsigned long arg) > > { > > @@ -1861,6 +1977,14 @@ long kvm_arch_vm_ioctl(struct file *filp, > > r = -EFAULT; > > break; > > } > > + case KVM_PPC_GET_CPU_CHAR: { > > + struct kvm_ppc_cpu_char cpuchar; > > + > > + r = kvmppc_get_cpu_char(&cpuchar); > > + if (r >= 0 && copy_to_user(argp, &cpuchar, sizeof(cpuchar))) > > + r = -EFAULT; > > + break; > > + } > > default: { > > struct kvm *kvm = filp->private_data; > > r = kvm->arch.kvm_ops->arch_vm_ioctl(filp, ioctl, arg); > > diff --git a/include/uapi/linux/kvm.h b/include/uapi/linux/kvm.h > > index 282d7613..e96e629 100644 > > --- a/include/uapi/linux/kvm.h > > +++ b/include/uapi/linux/kvm.h > > @@ -932,6 +932,7 @@ struct kvm_ppc_resize_hpt { > > #define KVM_CAP_HYPERV_SYNIC2 148 > > #define KVM_CAP_HYPERV_VP_INDEX 149 > > #define KVM_CAP_S390_AIS_MIGRATION 150 > > +#define KVM_CAP_PPC_GET_CPU_CHAR 151 > > > > #ifdef KVM_CAP_IRQ_ROUTING > > > > @@ -1261,6 +1262,8 @@ struct kvm_s390_ucas_mapping { > > #define KVM_PPC_CONFIGURE_V3_MMU _IOW(KVMIO, 0xaf, struct kvm_ppc_mmuv3_cfg) > > /* Available with KVM_CAP_PPC_RADIX_MMU */ > > #define KVM_PPC_GET_RMMU_INFO _IOW(KVMIO, 0xb0, struct kvm_ppc_rmmu_info) > > +/* Available with KVM_CAP_PPC_GET_CPU_CHAR */ > > +#define KVM_PPC_GET_CPU_CHAR _IOR(KVMIO, 0xb1, struct kvm_ppc_cpu_char) > > > > /* ioctl for vm fd */ > > #define KVM_CREATE_DEVICE _IOWR(KVMIO, 0xe0, struct kvm_create_device) > > > > Thanks, looks good. Would you like this in 4.15? Yes please. Will you just apply the patch, or do you want me to put it in a branch for you to pull? The patch depends on 191eccb15809 ("powerpc/pseries: Add H_GET_CPU_CHARACTERISTICS flags & wrapper", 2018-01-09) which is in Linus' tree as of v4.15-rc8, and I see that the kvm master branch is at rc8, so it should apply on the master branch just fine. Thanks, Paul. From mboxrd@z Thu Jan 1 00:00:00 1970 From: Paul Mackerras Date: Tue, 16 Jan 2018 21:51:00 +0000 Subject: Re: [PATCH] KVM: PPC: Book3S: Provide information about hardware/firmware CVE workarounds Message-Id: <20180116215100.GB15196@fergus.ozlabs.ibm.com> List-Id: References: <20180116005906.GA5434@fergus.ozlabs.ibm.com> <67f22a14-7192-bc55-b2ed-dfb2f3c33e03@redhat.com> In-Reply-To: <67f22a14-7192-bc55-b2ed-dfb2f3c33e03@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: Paolo Bonzini Cc: kvm@vger.kernel.org, kvm-ppc@vger.kernel.org, David Gibson , Radim =?utf-8?B?S3LEjW3DocWZ?= On Tue, Jan 16, 2018 at 03:45:11PM +0100, Paolo Bonzini wrote: > On 16/01/2018 01:59, Paul Mackerras wrote: > > This adds a new ioctl, KVM_PPC_GET_CPU_CHAR, that gives userspace > > information about the underlying machine's level of vulnerability > > to the recently announced vulnerabilities CVE-2017-5715, > > CVE-2017-5753 and CVE-2017-5754, and whether the machine provides > > instructions to assist software to work around the vulnerabilities. > > > > The ioctl returns two u64 words describing characteristics of the > > CPU and required software behaviour respectively, plus two mask > > words which indicate which bits have been filled in by the kernel, > > for extensibility. The bit definitions are the same as for the > > new H_GET_CPU_CHARACTERISTICS hypercall. > > > > There is also a new capability, KVM_CAP_PPC_GET_CPU_CHAR, which > > indicates whether the new ioctl is available. > > > > Signed-off-by: Paul Mackerras > > --- > > Documentation/virtual/kvm/api.txt | 46 +++++++++++++ > > arch/powerpc/include/uapi/asm/kvm.h | 22 +++++++ > > arch/powerpc/kvm/powerpc.c | 124 ++++++++++++++++++++++++++++++++++++ > > include/uapi/linux/kvm.h | 3 + > > 4 files changed, 195 insertions(+) > > > > diff --git a/Documentation/virtual/kvm/api.txt b/Documentation/virtual/kvm/api.txt > > index f670e4b..85ca84a 100644 > > --- a/Documentation/virtual/kvm/api.txt > > +++ b/Documentation/virtual/kvm/api.txt > > @@ -3394,6 +3394,52 @@ invalid, if invalid pages are written to (e.g. after the end of memory) > > or if no page table is present for the addresses (e.g. when using > > hugepages). > > > > +4.108 KVM_PPC_GET_CPU_CHAR > > + > > +Capability: KVM_CAP_PPC_GET_CPU_CHAR > > +Architectures: powerpc > > +Type: vm ioctl > > +Parameters: struct kvm_ppc_cpu_char (out) > > +Returns: 0 on successful completion > > + -EFAULT if struct kvm_ppc_cpu_char cannot be written > > + > > +This ioctl gives userspace information about certain characteristics > > +of the CPU relating to speculative execution of instructions and > > +possible information leakage resulting from speculative execution (see > > +CVE-2017-5715, CVE-2017-5753 and CVE-2017-5754). The information is > > +returned in struct kvm_ppc_cpu_char, which looks like this: > > + > > +struct kvm_ppc_cpu_char { > > + __u64 character; /* characteristics of the CPU */ > > + __u64 behaviour; /* recommended software behaviour */ > > + __u64 character_mask; /* valid bits in character */ > > + __u64 behaviour_mask; /* valid bits in behaviour */ > > +}; > > + > > +For extensibility, the character_mask and behaviour_mask fields > > +indicate which bits of character and behaviour have been filled in by > > +the kernel. If the set of defined bits is extended in future then > > +userspace will be able to tell whether it is running on a kernel that > > +knows about the new bits. > > + > > +The character field describes attributes of the CPU which can help > > +with preventing inadvertent information disclosure - specifically, > > +whether there is an instruction to flash-invalidate the L1 data cache > > +(ori 30,30,0 or mtspr SPRN_TRIG2,rN), whether the L1 data cache is set > > +to a mode where entries can only be used by the thread that created > > +them, whether the bcctr[l] instruction prevents speculation, and > > +whether a speculation barrier instruction (ori 31,31,0) is provided. > > + > > +The behaviour field describes actions that software should take to > > +prevent inadvertent information disclosure, and thus describes which > > +vulnerabilities the hardware is subject to; specifically whether the > > +L1 data cache should be flushed when returning to user mode from the > > +kernel, and whether a speculation barrier should be placed between an > > +array bounds check and the array access. > > + > > +These fields use the same bit definitions as the new > > +H_GET_CPU_CHARACTERISTICS hypercall. > > + > > 5. The kvm_run structure > > ------------------------ > > > > diff --git a/arch/powerpc/include/uapi/asm/kvm.h b/arch/powerpc/include/uapi/asm/kvm.h > > index 61d6049..ce74bed 100644 > > --- a/arch/powerpc/include/uapi/asm/kvm.h > > +++ b/arch/powerpc/include/uapi/asm/kvm.h > > @@ -443,6 +443,28 @@ struct kvm_ppc_rmmu_info { > > __u32 ap_encodings[8]; > > }; > > > > +/* For KVM_PPC_GET_CPU_CHAR */ > > +struct kvm_ppc_cpu_char { > > + __u64 character; /* characteristics of the CPU */ > > + __u64 behaviour; /* recommended software behaviour */ > > + __u64 character_mask; /* valid bits in character */ > > + __u64 behaviour_mask; /* valid bits in behaviour */ > > +}; > > + > > +/* > > + * Values for character and character_mask. > > + * These are identical to the values used by H_GET_CPU_CHARACTERISTICS. > > + */ > > +#define KVM_PPC_CPU_CHAR_SPEC_BAR_ORI31 (1ULL << 63) > > +#define KVM_PPC_CPU_CHAR_BCCTRL_SERIALISED (1ULL << 62) > > +#define KVM_PPC_CPU_CHAR_L1D_FLUSH_ORI30 (1ULL << 61) > > +#define KVM_PPC_CPU_CHAR_L1D_FLUSH_TRIG2 (1ULL << 60) > > +#define KVM_PPC_CPU_CHAR_L1D_THREAD_PRIV (1ULL << 59) > > + > > +#define KVM_PPC_CPU_BEHAV_FAVOUR_SECURITY (1ULL << 63) > > +#define KVM_PPC_CPU_BEHAV_L1D_FLUSH_PR (1ULL << 62) > > +#define KVM_PPC_CPU_BEHAV_BNDS_CHK_SPEC_BAR (1ULL << 61) > > + > > /* Per-vcpu XICS interrupt controller state */ > > #define KVM_REG_PPC_ICP_STATE (KVM_REG_PPC | KVM_REG_SIZE_U64 | 0x8c) > > > > diff --git a/arch/powerpc/kvm/powerpc.c b/arch/powerpc/kvm/powerpc.c > > index 1915e86..c9cecff 100644 > > --- a/arch/powerpc/kvm/powerpc.c > > +++ b/arch/powerpc/kvm/powerpc.c > > @@ -39,6 +39,10 @@ > > #include > > #include > > #include > > +#ifdef CONFIG_PPC_PSERIES > > +#include > > +#include > > +#endif > > > > #include "timing.h" > > #include "irq.h" > > @@ -548,6 +552,7 @@ int kvm_vm_ioctl_check_extension(struct kvm *kvm, long ext) > > #ifdef CONFIG_KVM_XICS > > case KVM_CAP_IRQ_XICS: > > #endif > > + case KVM_CAP_PPC_GET_CPU_CHAR: > > r = 1; > > break; > > > > @@ -1759,6 +1764,117 @@ static int kvm_vm_ioctl_enable_cap(struct kvm *kvm, > > return r; > > } > > > > +#ifdef CONFIG_PPC_BOOK3S_64 > > +/* > > + * These functions check whether the underlying hardware is safe > > + * against attacks based on observing the effects of speculatively > > + * executed instructions, and whether it supplies instructions for > > + * use in workarounds. The information comes from firmware, either > > + * via the device tree on powernv platforms or from an hcall on > > + * pseries platforms. > > + */ > > +#ifdef CONFIG_PPC_PSERIES > > +static int pseries_get_cpu_char(struct kvm_ppc_cpu_char *cp) > > +{ > > + struct h_cpu_char_result c; > > + unsigned long rc; > > + > > + if (!machine_is(pseries)) > > + return -ENOTTY; > > + > > + rc = plpar_get_cpu_characteristics(&c); > > + if (rc = H_SUCCESS) { > > + cp->character = c.character; > > + cp->behaviour = c.behaviour; > > + cp->character_mask = KVM_PPC_CPU_CHAR_SPEC_BAR_ORI31 | > > + KVM_PPC_CPU_CHAR_BCCTRL_SERIALISED | > > + KVM_PPC_CPU_CHAR_L1D_FLUSH_ORI30 | > > + KVM_PPC_CPU_CHAR_L1D_FLUSH_TRIG2 | > > + KVM_PPC_CPU_CHAR_L1D_THREAD_PRIV; > > + cp->behaviour_mask = KVM_PPC_CPU_BEHAV_FAVOUR_SECURITY | > > + KVM_PPC_CPU_BEHAV_L1D_FLUSH_PR | > > + KVM_PPC_CPU_BEHAV_BNDS_CHK_SPEC_BAR; > > + } > > + return 0; > > +} > > +#else > > +static int pseries_get_cpu_char(struct kvm_ppc_cpu_char *cp) > > +{ > > + return -ENOTTY; > > +} > > +#endif > > + > > +static inline bool have_fw_feat(struct device_node *fw_features, > > + const char *state, const char *name) > > +{ > > + struct device_node *np; > > + bool r = false; > > + > > + np = of_get_child_by_name(fw_features, name); > > + if (np) { > > + r = of_property_read_bool(np, state); > > + of_node_put(np); > > + } > > + return r; > > +} > > + > > +static int kvmppc_get_cpu_char(struct kvm_ppc_cpu_char *cp) > > +{ > > + struct device_node *np, *fw_features; > > + int r; > > + > > + memset(cp, 0, sizeof(*cp)); > > + r = pseries_get_cpu_char(cp); > > + if (r != -ENOTTY) > > + return r; > > + > > + np = of_find_node_by_name(NULL, "ibm,opal"); > > + if (np) { > > + fw_features = of_get_child_by_name(np, "fw-features"); > > + of_node_put(np); > > + if (!fw_features) > > + return 0; > > + if (have_fw_feat(fw_features, "enabled", > > + "inst-spec-barrier-ori31,31,0")) > > + cp->character |= KVM_PPC_CPU_CHAR_SPEC_BAR_ORI31; > > + if (have_fw_feat(fw_features, "enabled", > > + "fw-bcctrl-serialized")) > > + cp->character |= KVM_PPC_CPU_CHAR_BCCTRL_SERIALISED; > > + if (have_fw_feat(fw_features, "enabled", > > + "inst-l1d-flush-ori30,30,0")) > > + cp->character |= KVM_PPC_CPU_CHAR_L1D_FLUSH_ORI30; > > + if (have_fw_feat(fw_features, "enabled", > > + "inst-l1d-flush-trig2")) > > + cp->character |= KVM_PPC_CPU_CHAR_L1D_FLUSH_TRIG2; > > + if (have_fw_feat(fw_features, "enabled", > > + "fw-l1d-thread-split")) > > + cp->character |= KVM_PPC_CPU_CHAR_L1D_THREAD_PRIV; > > + cp->character_mask = KVM_PPC_CPU_CHAR_SPEC_BAR_ORI31 | > > + KVM_PPC_CPU_CHAR_BCCTRL_SERIALISED | > > + KVM_PPC_CPU_CHAR_L1D_FLUSH_ORI30 | > > + KVM_PPC_CPU_CHAR_L1D_FLUSH_TRIG2 | > > + KVM_PPC_CPU_CHAR_L1D_THREAD_PRIV; > > + > > + if (have_fw_feat(fw_features, "enabled", > > + "speculation-policy-favor-security")) > > + cp->behaviour |= KVM_PPC_CPU_BEHAV_FAVOUR_SECURITY; > > + if (!have_fw_feat(fw_features, "disabled", > > + "needs-l1d-flush-msr-pr-0-to-1")) > > + cp->behaviour |= KVM_PPC_CPU_BEHAV_L1D_FLUSH_PR; > > + if (!have_fw_feat(fw_features, "disabled", > > + "needs-spec-barrier-for-bound-checks")) > > + cp->behaviour |= KVM_PPC_CPU_BEHAV_BNDS_CHK_SPEC_BAR; > > + cp->behaviour_mask = KVM_PPC_CPU_BEHAV_FAVOUR_SECURITY | > > + KVM_PPC_CPU_BEHAV_L1D_FLUSH_PR | > > + KVM_PPC_CPU_BEHAV_BNDS_CHK_SPEC_BAR; > > + > > + of_node_put(fw_features); > > + } > > + > > + return 0; > > +} > > +#endif > > + > > long kvm_arch_vm_ioctl(struct file *filp, > > unsigned int ioctl, unsigned long arg) > > { > > @@ -1861,6 +1977,14 @@ long kvm_arch_vm_ioctl(struct file *filp, > > r = -EFAULT; > > break; > > } > > + case KVM_PPC_GET_CPU_CHAR: { > > + struct kvm_ppc_cpu_char cpuchar; > > + > > + r = kvmppc_get_cpu_char(&cpuchar); > > + if (r >= 0 && copy_to_user(argp, &cpuchar, sizeof(cpuchar))) > > + r = -EFAULT; > > + break; > > + } > > default: { > > struct kvm *kvm = filp->private_data; > > r = kvm->arch.kvm_ops->arch_vm_ioctl(filp, ioctl, arg); > > diff --git a/include/uapi/linux/kvm.h b/include/uapi/linux/kvm.h > > index 282d7613..e96e629 100644 > > --- a/include/uapi/linux/kvm.h > > +++ b/include/uapi/linux/kvm.h > > @@ -932,6 +932,7 @@ struct kvm_ppc_resize_hpt { > > #define KVM_CAP_HYPERV_SYNIC2 148 > > #define KVM_CAP_HYPERV_VP_INDEX 149 > > #define KVM_CAP_S390_AIS_MIGRATION 150 > > +#define KVM_CAP_PPC_GET_CPU_CHAR 151 > > > > #ifdef KVM_CAP_IRQ_ROUTING > > > > @@ -1261,6 +1262,8 @@ struct kvm_s390_ucas_mapping { > > #define KVM_PPC_CONFIGURE_V3_MMU _IOW(KVMIO, 0xaf, struct kvm_ppc_mmuv3_cfg) > > /* Available with KVM_CAP_PPC_RADIX_MMU */ > > #define KVM_PPC_GET_RMMU_INFO _IOW(KVMIO, 0xb0, struct kvm_ppc_rmmu_info) > > +/* Available with KVM_CAP_PPC_GET_CPU_CHAR */ > > +#define KVM_PPC_GET_CPU_CHAR _IOR(KVMIO, 0xb1, struct kvm_ppc_cpu_char) > > > > /* ioctl for vm fd */ > > #define KVM_CREATE_DEVICE _IOWR(KVMIO, 0xe0, struct kvm_create_device) > > > > Thanks, looks good. Would you like this in 4.15? Yes please. Will you just apply the patch, or do you want me to put it in a branch for you to pull? The patch depends on 191eccb15809 ("powerpc/pseries: Add H_GET_CPU_CHARACTERISTICS flags & wrapper", 2018-01-09) which is in Linus' tree as of v4.15-rc8, and I see that the kvm master branch is at rc8, so it should apply on the master branch just fine. Thanks, Paul.