linux_dsm_epyc7002/arch/arm64/include/asm/kvm_host.h
Dave Martin b3eb56b629 KVM: arm64/sve: Fix SVE trap restoration for non-current tasks
Commit e6b673b ("KVM: arm64: Optimise FPSIMD handling to reduce
guest/host thrashing") attempts to restore the configuration of
userspace SVE trapping via a call to fpsimd_bind_task_to_cpu(), but
the logic for determining when to do this is not correct.

The patch makes the errnoenous assumption that the only task that
may try to enter userspace with the currently loaded FPSIMD/SVE
register content is current.  This may not be the case however:  if
some other user task T is scheduled on the CPU during the execution
of the KVM run loop, and the vcpu does not try to use the registers
in the meantime, then T's state may be left there intact.  If T
happens to be the next task to enter userspace on this CPU then the
hooks for reloading the register state and configuring traps will
be skipped.

(Also, current never has SVE state at this point anyway and should
always have the trap enabled, as a side-effect of the ioctl()
syscall needed to reach the KVM run loop in the first place.)

This patch instead restores the state of the EL0 trap from the
state observed at the most recent vcpu_load(), ensuring that the
trap is set correctly for the loaded context (if any).

Fixes: e6b673b741 ("KVM: arm64: Optimise FPSIMD handling to reduce guest/host thrashing")
Signed-off-by: Dave Martin <Dave.Martin@arm.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2018-06-21 09:14:44 +01:00

517 lines
17 KiB
C

/*
* Copyright (C) 2012,2013 - ARM Ltd
* Author: Marc Zyngier <marc.zyngier@arm.com>
*
* Derived from arch/arm/include/asm/kvm_host.h:
* Copyright (C) 2012 - Virtual Open Systems and Columbia University
* Author: Christoffer Dall <c.dall@virtualopensystems.com>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
#ifndef __ARM64_KVM_HOST_H__
#define __ARM64_KVM_HOST_H__
#include <linux/types.h>
#include <linux/kvm_types.h>
#include <asm/cpufeature.h>
#include <asm/daifflags.h>
#include <asm/fpsimd.h>
#include <asm/kvm.h>
#include <asm/kvm_asm.h>
#include <asm/kvm_mmio.h>
#include <asm/thread_info.h>
#define __KVM_HAVE_ARCH_INTC_INITIALIZED
#define KVM_USER_MEM_SLOTS 512
#define KVM_HALT_POLL_NS_DEFAULT 500000
#include <kvm/arm_vgic.h>
#include <kvm/arm_arch_timer.h>
#include <kvm/arm_pmu.h>
#define KVM_MAX_VCPUS VGIC_V3_MAX_CPUS
#define KVM_VCPU_MAX_FEATURES 4
#define KVM_REQ_SLEEP \
KVM_ARCH_REQ_FLAGS(0, KVM_REQUEST_WAIT | KVM_REQUEST_NO_WAKEUP)
#define KVM_REQ_IRQ_PENDING KVM_ARCH_REQ(1)
DECLARE_STATIC_KEY_FALSE(userspace_irqchip_in_use);
int __attribute_const__ kvm_target_cpu(void);
int kvm_reset_vcpu(struct kvm_vcpu *vcpu);
int kvm_arch_dev_ioctl_check_extension(struct kvm *kvm, long ext);
void __extended_idmap_trampoline(phys_addr_t boot_pgd, phys_addr_t idmap_start);
struct kvm_arch {
/* The VMID generation used for the virt. memory system */
u64 vmid_gen;
u32 vmid;
/* 1-level 2nd stage table and lock */
spinlock_t pgd_lock;
pgd_t *pgd;
/* VTTBR value associated with above pgd and vmid */
u64 vttbr;
/* The last vcpu id that ran on each physical CPU */
int __percpu *last_vcpu_ran;
/* The maximum number of vCPUs depends on the used GIC model */
int max_vcpus;
/* Interrupt controller */
struct vgic_dist vgic;
/* Mandated version of PSCI */
u32 psci_version;
};
#define KVM_NR_MEM_OBJS 40
/*
* We don't want allocation failures within the mmu code, so we preallocate
* enough memory for a single page fault in a cache.
*/
struct kvm_mmu_memory_cache {
int nobjs;
void *objects[KVM_NR_MEM_OBJS];
};
struct kvm_vcpu_fault_info {
u32 esr_el2; /* Hyp Syndrom Register */
u64 far_el2; /* Hyp Fault Address Register */
u64 hpfar_el2; /* Hyp IPA Fault Address Register */
u64 disr_el1; /* Deferred [SError] Status Register */
};
/*
* 0 is reserved as an invalid value.
* Order should be kept in sync with the save/restore code.
*/
enum vcpu_sysreg {
__INVALID_SYSREG__,
MPIDR_EL1, /* MultiProcessor Affinity Register */
CSSELR_EL1, /* Cache Size Selection Register */
SCTLR_EL1, /* System Control Register */
ACTLR_EL1, /* Auxiliary Control Register */
CPACR_EL1, /* Coprocessor Access Control */
TTBR0_EL1, /* Translation Table Base Register 0 */
TTBR1_EL1, /* Translation Table Base Register 1 */
TCR_EL1, /* Translation Control Register */
ESR_EL1, /* Exception Syndrome Register */
AFSR0_EL1, /* Auxiliary Fault Status Register 0 */
AFSR1_EL1, /* Auxiliary Fault Status Register 1 */
FAR_EL1, /* Fault Address Register */
MAIR_EL1, /* Memory Attribute Indirection Register */
VBAR_EL1, /* Vector Base Address Register */
CONTEXTIDR_EL1, /* Context ID Register */
TPIDR_EL0, /* Thread ID, User R/W */
TPIDRRO_EL0, /* Thread ID, User R/O */
TPIDR_EL1, /* Thread ID, Privileged */
AMAIR_EL1, /* Aux Memory Attribute Indirection Register */
CNTKCTL_EL1, /* Timer Control Register (EL1) */
PAR_EL1, /* Physical Address Register */
MDSCR_EL1, /* Monitor Debug System Control Register */
MDCCINT_EL1, /* Monitor Debug Comms Channel Interrupt Enable Reg */
DISR_EL1, /* Deferred Interrupt Status Register */
/* Performance Monitors Registers */
PMCR_EL0, /* Control Register */
PMSELR_EL0, /* Event Counter Selection Register */
PMEVCNTR0_EL0, /* Event Counter Register (0-30) */
PMEVCNTR30_EL0 = PMEVCNTR0_EL0 + 30,
PMCCNTR_EL0, /* Cycle Counter Register */
PMEVTYPER0_EL0, /* Event Type Register (0-30) */
PMEVTYPER30_EL0 = PMEVTYPER0_EL0 + 30,
PMCCFILTR_EL0, /* Cycle Count Filter Register */
PMCNTENSET_EL0, /* Count Enable Set Register */
PMINTENSET_EL1, /* Interrupt Enable Set Register */
PMOVSSET_EL0, /* Overflow Flag Status Set Register */
PMSWINC_EL0, /* Software Increment Register */
PMUSERENR_EL0, /* User Enable Register */
/* 32bit specific registers. Keep them at the end of the range */
DACR32_EL2, /* Domain Access Control Register */
IFSR32_EL2, /* Instruction Fault Status Register */
FPEXC32_EL2, /* Floating-Point Exception Control Register */
DBGVCR32_EL2, /* Debug Vector Catch Register */
NR_SYS_REGS /* Nothing after this line! */
};
/* 32bit mapping */
#define c0_MPIDR (MPIDR_EL1 * 2) /* MultiProcessor ID Register */
#define c0_CSSELR (CSSELR_EL1 * 2)/* Cache Size Selection Register */
#define c1_SCTLR (SCTLR_EL1 * 2) /* System Control Register */
#define c1_ACTLR (ACTLR_EL1 * 2) /* Auxiliary Control Register */
#define c1_CPACR (CPACR_EL1 * 2) /* Coprocessor Access Control */
#define c2_TTBR0 (TTBR0_EL1 * 2) /* Translation Table Base Register 0 */
#define c2_TTBR0_high (c2_TTBR0 + 1) /* TTBR0 top 32 bits */
#define c2_TTBR1 (TTBR1_EL1 * 2) /* Translation Table Base Register 1 */
#define c2_TTBR1_high (c2_TTBR1 + 1) /* TTBR1 top 32 bits */
#define c2_TTBCR (TCR_EL1 * 2) /* Translation Table Base Control R. */
#define c3_DACR (DACR32_EL2 * 2)/* Domain Access Control Register */
#define c5_DFSR (ESR_EL1 * 2) /* Data Fault Status Register */
#define c5_IFSR (IFSR32_EL2 * 2)/* Instruction Fault Status Register */
#define c5_ADFSR (AFSR0_EL1 * 2) /* Auxiliary Data Fault Status R */
#define c5_AIFSR (AFSR1_EL1 * 2) /* Auxiliary Instr Fault Status R */
#define c6_DFAR (FAR_EL1 * 2) /* Data Fault Address Register */
#define c6_IFAR (c6_DFAR + 1) /* Instruction Fault Address Register */
#define c7_PAR (PAR_EL1 * 2) /* Physical Address Register */
#define c7_PAR_high (c7_PAR + 1) /* PAR top 32 bits */
#define c10_PRRR (MAIR_EL1 * 2) /* Primary Region Remap Register */
#define c10_NMRR (c10_PRRR + 1) /* Normal Memory Remap Register */
#define c12_VBAR (VBAR_EL1 * 2) /* Vector Base Address Register */
#define c13_CID (CONTEXTIDR_EL1 * 2) /* Context ID Register */
#define c13_TID_URW (TPIDR_EL0 * 2) /* Thread ID, User R/W */
#define c13_TID_URO (TPIDRRO_EL0 * 2)/* Thread ID, User R/O */
#define c13_TID_PRIV (TPIDR_EL1 * 2) /* Thread ID, Privileged */
#define c10_AMAIR0 (AMAIR_EL1 * 2) /* Aux Memory Attr Indirection Reg */
#define c10_AMAIR1 (c10_AMAIR0 + 1)/* Aux Memory Attr Indirection Reg */
#define c14_CNTKCTL (CNTKCTL_EL1 * 2) /* Timer Control Register (PL1) */
#define cp14_DBGDSCRext (MDSCR_EL1 * 2)
#define cp14_DBGBCR0 (DBGBCR0_EL1 * 2)
#define cp14_DBGBVR0 (DBGBVR0_EL1 * 2)
#define cp14_DBGBXVR0 (cp14_DBGBVR0 + 1)
#define cp14_DBGWCR0 (DBGWCR0_EL1 * 2)
#define cp14_DBGWVR0 (DBGWVR0_EL1 * 2)
#define cp14_DBGDCCINT (MDCCINT_EL1 * 2)
#define NR_COPRO_REGS (NR_SYS_REGS * 2)
struct kvm_cpu_context {
struct kvm_regs gp_regs;
union {
u64 sys_regs[NR_SYS_REGS];
u32 copro[NR_COPRO_REGS];
};
struct kvm_vcpu *__hyp_running_vcpu;
};
typedef struct kvm_cpu_context kvm_cpu_context_t;
struct kvm_vcpu_arch {
struct kvm_cpu_context ctxt;
/* HYP configuration */
u64 hcr_el2;
u32 mdcr_el2;
/* Exception Information */
struct kvm_vcpu_fault_info fault;
/* State of various workarounds, see kvm_asm.h for bit assignment */
u64 workaround_flags;
/* Miscellaneous vcpu state flags */
u64 flags;
/*
* We maintain more than a single set of debug registers to support
* debugging the guest from the host and to maintain separate host and
* guest state during world switches. vcpu_debug_state are the debug
* registers of the vcpu as the guest sees them. host_debug_state are
* the host registers which are saved and restored during
* world switches. external_debug_state contains the debug
* values we want to debug the guest. This is set via the
* KVM_SET_GUEST_DEBUG ioctl.
*
* debug_ptr points to the set of debug registers that should be loaded
* onto the hardware when running the guest.
*/
struct kvm_guest_debug_arch *debug_ptr;
struct kvm_guest_debug_arch vcpu_debug_state;
struct kvm_guest_debug_arch external_debug_state;
/* Pointer to host CPU context */
kvm_cpu_context_t *host_cpu_context;
struct thread_info *host_thread_info; /* hyp VA */
struct user_fpsimd_state *host_fpsimd_state; /* hyp VA */
struct {
/* {Break,watch}point registers */
struct kvm_guest_debug_arch regs;
/* Statistical profiling extension */
u64 pmscr_el1;
} host_debug_state;
/* VGIC state */
struct vgic_cpu vgic_cpu;
struct arch_timer_cpu timer_cpu;
struct kvm_pmu pmu;
/*
* Anything that is not used directly from assembly code goes
* here.
*/
/*
* Guest registers we preserve during guest debugging.
*
* These shadow registers are updated by the kvm_handle_sys_reg
* trap handler if the guest accesses or updates them while we
* are using guest debug.
*/
struct {
u32 mdscr_el1;
} guest_debug_preserved;
/* vcpu power-off state */
bool power_off;
/* Don't run the guest (internal implementation need) */
bool pause;
/* IO related fields */
struct kvm_decode mmio_decode;
/* Cache some mmu pages needed inside spinlock regions */
struct kvm_mmu_memory_cache mmu_page_cache;
/* Target CPU and feature flags */
int target;
DECLARE_BITMAP(features, KVM_VCPU_MAX_FEATURES);
/* Detect first run of a vcpu */
bool has_run_once;
/* Virtual SError ESR to restore when HCR_EL2.VSE is set */
u64 vsesr_el2;
/* True when deferrable sysregs are loaded on the physical CPU,
* see kvm_vcpu_load_sysregs and kvm_vcpu_put_sysregs. */
bool sysregs_loaded_on_cpu;
};
/* vcpu_arch flags field values: */
#define KVM_ARM64_DEBUG_DIRTY (1 << 0)
#define KVM_ARM64_FP_ENABLED (1 << 1) /* guest FP regs loaded */
#define KVM_ARM64_FP_HOST (1 << 2) /* host FP regs loaded */
#define KVM_ARM64_HOST_SVE_IN_USE (1 << 3) /* backup for host TIF_SVE */
#define KVM_ARM64_HOST_SVE_ENABLED (1 << 4) /* SVE enabled for EL0 */
#define vcpu_gp_regs(v) (&(v)->arch.ctxt.gp_regs)
/*
* Only use __vcpu_sys_reg if you know you want the memory backed version of a
* register, and not the one most recently accessed by a running VCPU. For
* example, for userspace access or for system registers that are never context
* switched, but only emulated.
*/
#define __vcpu_sys_reg(v,r) ((v)->arch.ctxt.sys_regs[(r)])
u64 vcpu_read_sys_reg(struct kvm_vcpu *vcpu, int reg);
void vcpu_write_sys_reg(struct kvm_vcpu *vcpu, u64 val, int reg);
/*
* CP14 and CP15 live in the same array, as they are backed by the
* same system registers.
*/
#define vcpu_cp14(v,r) ((v)->arch.ctxt.copro[(r)])
#define vcpu_cp15(v,r) ((v)->arch.ctxt.copro[(r)])
struct kvm_vm_stat {
ulong remote_tlb_flush;
};
struct kvm_vcpu_stat {
u64 halt_successful_poll;
u64 halt_attempted_poll;
u64 halt_poll_invalid;
u64 halt_wakeup;
u64 hvc_exit_stat;
u64 wfe_exit_stat;
u64 wfi_exit_stat;
u64 mmio_exit_user;
u64 mmio_exit_kernel;
u64 exits;
};
int kvm_vcpu_preferred_target(struct kvm_vcpu_init *init);
unsigned long kvm_arm_num_regs(struct kvm_vcpu *vcpu);
int kvm_arm_copy_reg_indices(struct kvm_vcpu *vcpu, u64 __user *indices);
int kvm_arm_get_reg(struct kvm_vcpu *vcpu, const struct kvm_one_reg *reg);
int kvm_arm_set_reg(struct kvm_vcpu *vcpu, const struct kvm_one_reg *reg);
#define KVM_ARCH_WANT_MMU_NOTIFIER
int kvm_unmap_hva(struct kvm *kvm, unsigned long hva);
int kvm_unmap_hva_range(struct kvm *kvm,
unsigned long start, unsigned long end);
void kvm_set_spte_hva(struct kvm *kvm, unsigned long hva, pte_t pte);
int kvm_age_hva(struct kvm *kvm, unsigned long start, unsigned long end);
int kvm_test_age_hva(struct kvm *kvm, unsigned long hva);
struct kvm_vcpu *kvm_arm_get_running_vcpu(void);
struct kvm_vcpu * __percpu *kvm_get_running_vcpus(void);
void kvm_arm_halt_guest(struct kvm *kvm);
void kvm_arm_resume_guest(struct kvm *kvm);
u64 __kvm_call_hyp(void *hypfn, ...);
#define kvm_call_hyp(f, ...) __kvm_call_hyp(kvm_ksym_ref(f), ##__VA_ARGS__)
void force_vm_exit(const cpumask_t *mask);
void kvm_mmu_wp_memory_region(struct kvm *kvm, int slot);
int handle_exit(struct kvm_vcpu *vcpu, struct kvm_run *run,
int exception_index);
void handle_exit_early(struct kvm_vcpu *vcpu, struct kvm_run *run,
int exception_index);
int kvm_perf_init(void);
int kvm_perf_teardown(void);
struct kvm_vcpu *kvm_mpidr_to_vcpu(struct kvm *kvm, unsigned long mpidr);
void __kvm_set_tpidr_el2(u64 tpidr_el2);
DECLARE_PER_CPU(kvm_cpu_context_t, kvm_host_cpu_state);
static inline void __cpu_init_hyp_mode(phys_addr_t pgd_ptr,
unsigned long hyp_stack_ptr,
unsigned long vector_ptr)
{
u64 tpidr_el2;
/*
* Call initialization code, and switch to the full blown HYP code.
* If the cpucaps haven't been finalized yet, something has gone very
* wrong, and hyp will crash and burn when it uses any
* cpus_have_const_cap() wrapper.
*/
BUG_ON(!static_branch_likely(&arm64_const_caps_ready));
__kvm_call_hyp((void *)pgd_ptr, hyp_stack_ptr, vector_ptr);
/*
* Calculate the raw per-cpu offset without a translation from the
* kernel's mapping to the linear mapping, and store it in tpidr_el2
* so that we can use adr_l to access per-cpu variables in EL2.
*/
tpidr_el2 = (u64)this_cpu_ptr(&kvm_host_cpu_state)
- (u64)kvm_ksym_ref(kvm_host_cpu_state);
kvm_call_hyp(__kvm_set_tpidr_el2, tpidr_el2);
}
static inline bool kvm_arch_check_sve_has_vhe(void)
{
/*
* The Arm architecture specifies that implementation of SVE
* requires VHE also to be implemented. The KVM code for arm64
* relies on this when SVE is present:
*/
if (system_supports_sve())
return has_vhe();
else
return true;
}
static inline void kvm_arch_hardware_unsetup(void) {}
static inline void kvm_arch_sync_events(struct kvm *kvm) {}
static inline void kvm_arch_vcpu_uninit(struct kvm_vcpu *vcpu) {}
static inline void kvm_arch_sched_in(struct kvm_vcpu *vcpu, int cpu) {}
static inline void kvm_arch_vcpu_block_finish(struct kvm_vcpu *vcpu) {}
void kvm_arm_init_debug(void);
void kvm_arm_setup_debug(struct kvm_vcpu *vcpu);
void kvm_arm_clear_debug(struct kvm_vcpu *vcpu);
void kvm_arm_reset_debug_ptr(struct kvm_vcpu *vcpu);
bool kvm_arm_handle_step_debug(struct kvm_vcpu *vcpu, struct kvm_run *run);
int kvm_arm_vcpu_arch_set_attr(struct kvm_vcpu *vcpu,
struct kvm_device_attr *attr);
int kvm_arm_vcpu_arch_get_attr(struct kvm_vcpu *vcpu,
struct kvm_device_attr *attr);
int kvm_arm_vcpu_arch_has_attr(struct kvm_vcpu *vcpu,
struct kvm_device_attr *attr);
static inline void __cpu_init_stage2(void)
{
u32 parange = kvm_call_hyp(__init_stage2_translation);
WARN_ONCE(parange < 40,
"PARange is %d bits, unsupported configuration!", parange);
}
/* Guest/host FPSIMD coordination helpers */
int kvm_arch_vcpu_run_map_fp(struct kvm_vcpu *vcpu);
void kvm_arch_vcpu_load_fp(struct kvm_vcpu *vcpu);
void kvm_arch_vcpu_ctxsync_fp(struct kvm_vcpu *vcpu);
void kvm_arch_vcpu_put_fp(struct kvm_vcpu *vcpu);
#ifdef CONFIG_KVM /* Avoid conflicts with core headers if CONFIG_KVM=n */
static inline int kvm_arch_vcpu_run_pid_change(struct kvm_vcpu *vcpu)
{
return kvm_arch_vcpu_run_map_fp(vcpu);
}
#endif
static inline void kvm_arm_vhe_guest_enter(void)
{
local_daif_mask();
}
static inline void kvm_arm_vhe_guest_exit(void)
{
local_daif_restore(DAIF_PROCCTX_NOIRQ);
/*
* When we exit from the guest we change a number of CPU configuration
* parameters, such as traps. Make sure these changes take effect
* before running the host or additional guests.
*/
isb();
}
static inline bool kvm_arm_harden_branch_predictor(void)
{
return cpus_have_const_cap(ARM64_HARDEN_BRANCH_PREDICTOR);
}
#define KVM_SSBD_UNKNOWN -1
#define KVM_SSBD_FORCE_DISABLE 0
#define KVM_SSBD_KERNEL 1
#define KVM_SSBD_FORCE_ENABLE 2
#define KVM_SSBD_MITIGATED 3
static inline int kvm_arm_have_ssbd(void)
{
switch (arm64_get_ssbd_state()) {
case ARM64_SSBD_FORCE_DISABLE:
return KVM_SSBD_FORCE_DISABLE;
case ARM64_SSBD_KERNEL:
return KVM_SSBD_KERNEL;
case ARM64_SSBD_FORCE_ENABLE:
return KVM_SSBD_FORCE_ENABLE;
case ARM64_SSBD_MITIGATED:
return KVM_SSBD_MITIGATED;
case ARM64_SSBD_UNKNOWN:
default:
return KVM_SSBD_UNKNOWN;
}
}
void kvm_vcpu_load_sysregs(struct kvm_vcpu *vcpu);
void kvm_vcpu_put_sysregs(struct kvm_vcpu *vcpu);
#define __KVM_HAVE_ARCH_VM_ALLOC
struct kvm *kvm_arch_alloc_vm(void);
void kvm_arch_free_vm(struct kvm *kvm);
#endif /* __ARM64_KVM_HOST_H__ */