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KVM fixes for v4.15-rc9

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ARM:
 * fix incorrect huge page mappings on systems using the contiguous hint
   for hugetlbfs
 * support alternative GICv4 init sequence
 * correctly implement the ARM SMCC for HVC and SMC handling
 
 PPC:
 * add KVM IOCTL for reporting vulnerability and workaround status
 
 s390:
 * provide userspace interface for branch prediction changes in firmware
 
 x86:
 * use correct macros for bits
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Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm

Pull KVM fixes from Radim Krčmář:
 "ARM:
   - fix incorrect huge page mappings on systems using the contiguous
     hint for hugetlbfs
   - support alternative GICv4 init sequence
   - correctly implement the ARM SMCC for HVC and SMC handling

  PPC:
   - add KVM IOCTL for reporting vulnerability and workaround status

  s390:
   - provide userspace interface for branch prediction changes in
     firmware

  x86:
   - use correct macros for bits"

* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm:
  KVM: s390: wire up bpb feature
  KVM: PPC: Book3S: Provide information about hardware/firmware CVE workarounds
  KVM/x86: Fix wrong macro references of X86_CR0_PG_BIT and X86_CR4_PAE_BIT in kvm_valid_sregs()
  arm64: KVM: Fix SMCCC handling of unimplemented SMC/HVC calls
  KVM: arm64: Fix GICv4 init when called from vgic_its_create
  KVM: arm/arm64: Check pagesize when allocating a hugepage at Stage 2
This commit is contained in:
Linus Torvalds 2018-01-20 11:41:09 -08:00
commit 24b6124047
13 changed files with 245 additions and 11 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

46
Documentation/virtual/kvm/api.txt
View File

@ -3403,6 +3403,52 @@ 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
------------------------

4
arch/arm64/kvm/handle_exit.c
View File

@ -45,7 +45,7 @@ static int handle_hvc(struct kvm_vcpu *vcpu, struct kvm_run *run)
ret = kvm_psci_call(vcpu);
if (ret < 0) {
kvm_inject_undefined(vcpu);
vcpu_set_reg(vcpu, 0, ~0UL);
return 1;
}
@ -54,7 +54,7 @@ static int handle_hvc(struct kvm_vcpu *vcpu, struct kvm_run *run)
static int handle_smc(struct kvm_vcpu *vcpu, struct kvm_run *run)
{
kvm_inject_undefined(vcpu);
vcpu_set_reg(vcpu, 0, ~0UL);
return 1;
}

25
arch/powerpc/include/uapi/asm/kvm.h
View File

@ -443,6 +443,31 @@ 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_CHAR_BR_HINT_HONOURED (1ULL << 58)
#define KVM_PPC_CPU_CHAR_MTTRIG_THR_RECONF (1ULL << 57)
#define KVM_PPC_CPU_CHAR_COUNT_CACHE_DIS (1ULL << 56)
#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)

131
arch/powerpc/kvm/powerpc.c
View File

@ -39,6 +39,10 @@
#include <asm/iommu.h>
#include <asm/switch_to.h>
#include <asm/xive.h>
#ifdef CONFIG_PPC_PSERIES
#include <asm/hvcall.h>
#include <asm/plpar_wrappers.h>
#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 +1764,124 @@ 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 |
KVM_PPC_CPU_CHAR_BR_HINT_HONOURED |
KVM_PPC_CPU_CHAR_MTTRIG_THR_RECONF |
KVM_PPC_CPU_CHAR_COUNT_CACHE_DIS;
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;
if (have_fw_feat(fw_features, "enabled",
"fw-count-cache-disabled"))
cp->character |= KVM_PPC_CPU_CHAR_COUNT_CACHE_DIS;
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 |
KVM_PPC_CPU_CHAR_COUNT_CACHE_DIS;
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 +1984,14 @@ 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);

3
arch/s390/include/asm/kvm_host.h
View File

@ -207,7 +207,8 @@ struct kvm_s390_sie_block {
__u16 ipa; /* 0x0056 */
__u32 ipb; /* 0x0058 */
__u32 scaoh; /* 0x005c */
__u8 reserved60; /* 0x0060 */
#define FPF_BPBC 0x20
__u8 fpf; /* 0x0060 */
#define ECB_GS 0x40
#define ECB_TE 0x10
#define ECB_SRSI 0x04

5
arch/s390/include/uapi/asm/kvm.h
View File

@ -224,6 +224,7 @@ struct kvm_guest_debug_arch {
#define KVM_SYNC_RICCB (1UL << 7)
#define KVM_SYNC_FPRS (1UL << 8)
#define KVM_SYNC_GSCB (1UL << 9)
#define KVM_SYNC_BPBC (1UL << 10)
/* length and alignment of the sdnx as a power of two */
#define SDNXC 8
#define SDNXL (1UL << SDNXC)
@ -247,7 +248,9 @@ struct kvm_sync_regs {
};
__u8 reserved[512]; /* for future vector expansion */
__u32 fpc; /* valid on KVM_SYNC_VRS or KVM_SYNC_FPRS */
__u8 padding1[52]; /* riccb needs to be 64byte aligned */
__u8 bpbc : 1; /* bp mode */
__u8 reserved2 : 7;
__u8 padding1[51]; /* riccb needs to be 64byte aligned */
__u8 riccb[64]; /* runtime instrumentation controls block */
__u8 padding2[192]; /* sdnx needs to be 256byte aligned */
union {

12
arch/s390/kvm/kvm-s390.c
View File

@ -421,6 +421,9 @@ int kvm_vm_ioctl_check_extension(struct kvm *kvm, long ext)
case KVM_CAP_S390_GS:
r = test_facility(133);
break;
case KVM_CAP_S390_BPB:
r = test_facility(82);
break;
default:
r = 0;
}
@ -2198,6 +2201,8 @@ int kvm_arch_vcpu_init(struct kvm_vcpu *vcpu)
kvm_s390_set_prefix(vcpu, 0);
if (test_kvm_facility(vcpu->kvm, 64))
vcpu->run->kvm_valid_regs |= KVM_SYNC_RICCB;
if (test_kvm_facility(vcpu->kvm, 82))
vcpu->run->kvm_valid_regs |= KVM_SYNC_BPBC;
if (test_kvm_facility(vcpu->kvm, 133))
vcpu->run->kvm_valid_regs |= KVM_SYNC_GSCB;
/* fprs can be synchronized via vrs, even if the guest has no vx. With
@ -2339,6 +2344,7 @@ static void kvm_s390_vcpu_initial_reset(struct kvm_vcpu *vcpu)
current->thread.fpu.fpc = 0;
vcpu->arch.sie_block->gbea = 1;
vcpu->arch.sie_block->pp = 0;
vcpu->arch.sie_block->fpf &= ~FPF_BPBC;
vcpu->arch.pfault_token = KVM_S390_PFAULT_TOKEN_INVALID;
kvm_clear_async_pf_completion_queue(vcpu);
if (!kvm_s390_user_cpu_state_ctrl(vcpu->kvm))
@ -3298,6 +3304,11 @@ static void sync_regs(struct kvm_vcpu *vcpu, struct kvm_run *kvm_run)
vcpu->arch.sie_block->ecd |= ECD_HOSTREGMGMT;
vcpu->arch.gs_enabled = 1;
}
if ((kvm_run->kvm_dirty_regs & KVM_SYNC_BPBC) &&
test_kvm_facility(vcpu->kvm, 82)) {
vcpu->arch.sie_block->fpf &= ~FPF_BPBC;
vcpu->arch.sie_block->fpf |= kvm_run->s.regs.bpbc ? FPF_BPBC : 0;
}
save_access_regs(vcpu->arch.host_acrs);
restore_access_regs(vcpu->run->s.regs.acrs);
/* save host (userspace) fprs/vrs */
@ -3344,6 +3355,7 @@ static void store_regs(struct kvm_vcpu *vcpu, struct kvm_run *kvm_run)
kvm_run->s.regs.pft = vcpu->arch.pfault_token;
kvm_run->s.regs.pfs = vcpu->arch.pfault_select;
kvm_run->s.regs.pfc = vcpu->arch.pfault_compare;
kvm_run->s.regs.bpbc = (vcpu->arch.sie_block->fpf & FPF_BPBC) == FPF_BPBC;
save_access_regs(vcpu->run->s.regs.acrs);
restore_access_regs(vcpu->arch.host_acrs);
/* Save guest register state */

10
arch/s390/kvm/vsie.c
View File

@ -223,6 +223,12 @@ static void unshadow_scb(struct kvm_vcpu *vcpu, struct vsie_page *vsie_page)
memcpy(scb_o->gcr, scb_s->gcr, 128);
scb_o->pp = scb_s->pp;
/* branch prediction */
if (test_kvm_facility(vcpu->kvm, 82)) {
scb_o->fpf &= ~FPF_BPBC;
scb_o->fpf |= scb_s->fpf & FPF_BPBC;
}
/* interrupt intercept */
switch (scb_s->icptcode) {
case ICPT_PROGI:
@ -265,6 +271,7 @@ static int shadow_scb(struct kvm_vcpu *vcpu, struct vsie_page *vsie_page)
scb_s->ecb3 = 0;
scb_s->ecd = 0;
scb_s->fac = 0;
scb_s->fpf = 0;
rc = prepare_cpuflags(vcpu, vsie_page);
if (rc)
@ -324,6 +331,9 @@ static int shadow_scb(struct kvm_vcpu *vcpu, struct vsie_page *vsie_page)
prefix_unmapped(vsie_page);
scb_s->ecb |= scb_o->ecb & ECB_TE;
}
/* branch prediction */
if (test_kvm_facility(vcpu->kvm, 82))
scb_s->fpf |= scb_o->fpf & FPF_BPBC;
/* SIMD */
if (test_kvm_facility(vcpu->kvm, 129)) {
scb_s->eca |= scb_o->eca & ECA_VX;

4
arch/x86/kvm/x86.c
View File

@ -7496,13 +7496,13 @@ EXPORT_SYMBOL_GPL(kvm_task_switch);
int kvm_valid_sregs(struct kvm_vcpu *vcpu, struct kvm_sregs *sregs)
{
if ((sregs->efer & EFER_LME) && (sregs->cr0 & X86_CR0_PG_BIT)) {
if ((sregs->efer & EFER_LME) && (sregs->cr0 & X86_CR0_PG)) {
/*
* When EFER.LME and CR0.PG are set, the processor is in
* 64-bit mode (though maybe in a 32-bit code segment).
* CR4.PAE and EFER.LMA must be set.
*/
if (!(sregs->cr4 & X86_CR4_PAE_BIT)
if (!(sregs->cr4 & X86_CR4_PAE)
|| !(sregs->efer & EFER_LMA))
return -EINVAL;
} else {

4
include/uapi/linux/kvm.h
View File

@ -932,6 +932,8 @@ 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
#define KVM_CAP_S390_BPB 152
#ifdef KVM_CAP_IRQ_ROUTING
@ -1261,6 +1263,8 @@ 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)

2
virt/kvm/arm/mmu.c
View File

@ -1310,7 +1310,7 @@ static int user_mem_abort(struct kvm_vcpu *vcpu, phys_addr_t fault_ipa,
return -EFAULT;
}
if (is_vm_hugetlb_page(vma) && !logging_active) {
if (vma_kernel_pagesize(vma) == PMD_SIZE && !logging_active) {
hugetlb = true;
gfn = (fault_ipa & PMD_MASK) >> PAGE_SHIFT;
} else {

8
virt/kvm/arm/vgic/vgic-init.c
View File

@ -285,9 +285,11 @@ int vgic_init(struct kvm *kvm)
if (ret)
goto out;
ret = vgic_v4_init(kvm);
if (ret)
goto out;
if (vgic_has_its(kvm)) {
ret = vgic_v4_init(kvm);
if (ret)
goto out;
}
kvm_for_each_vcpu(i, vcpu, kvm)
kvm_vgic_vcpu_enable(vcpu);

2
virt/kvm/arm/vgic/vgic-v4.c
View File

@ -118,7 +118,7 @@ int vgic_v4_init(struct kvm *kvm)
struct kvm_vcpu *vcpu;
int i, nr_vcpus, ret;
if (!vgic_supports_direct_msis(kvm))
if (!kvm_vgic_global_state.has_gicv4)
return 0; /* Nothing to see here... move along. */
if (dist->its_vm.vpes)