mirror of
https://github.com/AuxXxilium/linux_dsm_epyc7002.git
synced 2024-12-28 11:18:45 +07:00
54b8c7cbc5
The only external user of fpsimd_save() and fpsimd_flush_cpu_state() is the KVM FPSIMD code. A following patch will introduce a mechanism to acquire owernship of the FPSIMD/SVE context for performing context management operations. Rather than having to export the new helpers to get/put the context, we can just introduce a new function to combine fpsimd_save() and fpsimd_flush_cpu_state(). This has also the advantage to remove any external call of fpsimd_save() and fpsimd_flush_cpu_state(), so they can be turned static. Lastly, the new function can also be used in the PM notifier. Reviewed-by: Dave Martin <Dave.Martin@arm.com> Acked-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Julien Grall <julien.grall@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
138 lines
4.0 KiB
C
138 lines
4.0 KiB
C
// SPDX-License-Identifier: GPL-2.0
|
|
/*
|
|
* arch/arm64/kvm/fpsimd.c: Guest/host FPSIMD context coordination helpers
|
|
*
|
|
* Copyright 2018 Arm Limited
|
|
* Author: Dave Martin <Dave.Martin@arm.com>
|
|
*/
|
|
#include <linux/irqflags.h>
|
|
#include <linux/sched.h>
|
|
#include <linux/thread_info.h>
|
|
#include <linux/kvm_host.h>
|
|
#include <asm/fpsimd.h>
|
|
#include <asm/kvm_asm.h>
|
|
#include <asm/kvm_host.h>
|
|
#include <asm/kvm_mmu.h>
|
|
#include <asm/sysreg.h>
|
|
|
|
/*
|
|
* Called on entry to KVM_RUN unless this vcpu previously ran at least
|
|
* once and the most recent prior KVM_RUN for this vcpu was called from
|
|
* the same task as current (highly likely).
|
|
*
|
|
* This is guaranteed to execute before kvm_arch_vcpu_load_fp(vcpu),
|
|
* such that on entering hyp the relevant parts of current are already
|
|
* mapped.
|
|
*/
|
|
int kvm_arch_vcpu_run_map_fp(struct kvm_vcpu *vcpu)
|
|
{
|
|
int ret;
|
|
|
|
struct thread_info *ti = ¤t->thread_info;
|
|
struct user_fpsimd_state *fpsimd = ¤t->thread.uw.fpsimd_state;
|
|
|
|
/*
|
|
* Make sure the host task thread flags and fpsimd state are
|
|
* visible to hyp:
|
|
*/
|
|
ret = create_hyp_mappings(ti, ti + 1, PAGE_HYP);
|
|
if (ret)
|
|
goto error;
|
|
|
|
ret = create_hyp_mappings(fpsimd, fpsimd + 1, PAGE_HYP);
|
|
if (ret)
|
|
goto error;
|
|
|
|
vcpu->arch.host_thread_info = kern_hyp_va(ti);
|
|
vcpu->arch.host_fpsimd_state = kern_hyp_va(fpsimd);
|
|
error:
|
|
return ret;
|
|
}
|
|
|
|
/*
|
|
* Prepare vcpu for saving the host's FPSIMD state and loading the guest's.
|
|
* The actual loading is done by the FPSIMD access trap taken to hyp.
|
|
*
|
|
* Here, we just set the correct metadata to indicate that the FPSIMD
|
|
* state in the cpu regs (if any) belongs to current on the host.
|
|
*
|
|
* TIF_SVE is backed up here, since it may get clobbered with guest state.
|
|
* This flag is restored by kvm_arch_vcpu_put_fp(vcpu).
|
|
*/
|
|
void kvm_arch_vcpu_load_fp(struct kvm_vcpu *vcpu)
|
|
{
|
|
BUG_ON(!current->mm);
|
|
|
|
vcpu->arch.flags &= ~(KVM_ARM64_FP_ENABLED |
|
|
KVM_ARM64_HOST_SVE_IN_USE |
|
|
KVM_ARM64_HOST_SVE_ENABLED);
|
|
vcpu->arch.flags |= KVM_ARM64_FP_HOST;
|
|
|
|
if (test_thread_flag(TIF_SVE))
|
|
vcpu->arch.flags |= KVM_ARM64_HOST_SVE_IN_USE;
|
|
|
|
if (read_sysreg(cpacr_el1) & CPACR_EL1_ZEN_EL0EN)
|
|
vcpu->arch.flags |= KVM_ARM64_HOST_SVE_ENABLED;
|
|
}
|
|
|
|
/*
|
|
* If the guest FPSIMD state was loaded, update the host's context
|
|
* tracking data mark the CPU FPSIMD regs as dirty and belonging to vcpu
|
|
* so that they will be written back if the kernel clobbers them due to
|
|
* kernel-mode NEON before re-entry into the guest.
|
|
*/
|
|
void kvm_arch_vcpu_ctxsync_fp(struct kvm_vcpu *vcpu)
|
|
{
|
|
WARN_ON_ONCE(!irqs_disabled());
|
|
|
|
if (vcpu->arch.flags & KVM_ARM64_FP_ENABLED) {
|
|
fpsimd_bind_state_to_cpu(&vcpu->arch.ctxt.gp_regs.fp_regs,
|
|
vcpu->arch.sve_state,
|
|
vcpu->arch.sve_max_vl);
|
|
|
|
clear_thread_flag(TIF_FOREIGN_FPSTATE);
|
|
update_thread_flag(TIF_SVE, vcpu_has_sve(vcpu));
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Write back the vcpu FPSIMD regs if they are dirty, and invalidate the
|
|
* cpu FPSIMD regs so that they can't be spuriously reused if this vcpu
|
|
* disappears and another task or vcpu appears that recycles the same
|
|
* struct fpsimd_state.
|
|
*/
|
|
void kvm_arch_vcpu_put_fp(struct kvm_vcpu *vcpu)
|
|
{
|
|
unsigned long flags;
|
|
bool host_has_sve = system_supports_sve();
|
|
bool guest_has_sve = vcpu_has_sve(vcpu);
|
|
|
|
local_irq_save(flags);
|
|
|
|
if (vcpu->arch.flags & KVM_ARM64_FP_ENABLED) {
|
|
u64 *guest_zcr = &vcpu->arch.ctxt.sys_regs[ZCR_EL1];
|
|
|
|
fpsimd_save_and_flush_cpu_state();
|
|
|
|
if (guest_has_sve)
|
|
*guest_zcr = read_sysreg_s(SYS_ZCR_EL12);
|
|
} else if (host_has_sve) {
|
|
/*
|
|
* The FPSIMD/SVE state in the CPU has not been touched, and we
|
|
* have SVE (and VHE): CPACR_EL1 (alias CPTR_EL2) has been
|
|
* reset to CPACR_EL1_DEFAULT by the Hyp code, disabling SVE
|
|
* for EL0. To avoid spurious traps, restore the trap state
|
|
* seen by kvm_arch_vcpu_load_fp():
|
|
*/
|
|
if (vcpu->arch.flags & KVM_ARM64_HOST_SVE_ENABLED)
|
|
sysreg_clear_set(CPACR_EL1, 0, CPACR_EL1_ZEN_EL0EN);
|
|
else
|
|
sysreg_clear_set(CPACR_EL1, CPACR_EL1_ZEN_EL0EN, 0);
|
|
}
|
|
|
|
update_thread_flag(TIF_SVE,
|
|
vcpu->arch.flags & KVM_ARM64_HOST_SVE_IN_USE);
|
|
|
|
local_irq_restore(flags);
|
|
}
|