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Commit 24b61240 authored by Linus Torvalds's avatar Linus Torvalds
Browse files

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
parents e6252e7f 35b3fde6

Documentation/virtual/kvm/api.txt

+46 −0
Original line number Diff line number Diff line
@@ -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

------------------------

arch/arm64/kvm/handle_exit.c

+2 −2
Original line number Diff line number Diff line
@@ -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;

}

arch/powerpc/include/uapi/asm/kvm.h

+25 −0
Original line number Diff line number Diff line
@@ -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)

arch/powerpc/kvm/powerpc.c

+131 −0
Original line number Diff line number Diff line
@@ -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);

arch/s390/include/asm/kvm_host.h

+2 −1
Original line number Diff line number Diff line
@@ -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