[PATCH v4 13/40] KVM: arm64: Introduce VHE-specific kvm_vcpu_run
From: Christoffer Dall <hidden>
Date: 2018-02-15 21:03:05
Also in:
kvm, kvmarm
Subsystem:
arm port, arm64 port (aarch64 architecture), kernel virtual machine (kvm), kernel virtual machine for arm64 (kvm/arm64), the rest · Maintainers:
Russell King, Catalin Marinas, Will Deacon, Paolo Bonzini, Marc Zyngier, Oliver Upton, Linus Torvalds
So far this is mostly (see below) a copy of the legacy non-VHE switch
function, but we will start reworking these functions in separate
directions to work on VHE and non-VHE in the most optimal way in later
patches.
The only difference after this patch between the VHE and non-VHE run
functions is that we omit the branch-predictor variant-2 hardening for
QC Falkor CPUs, because this workaround is specific to a series of
non-VHE ARMv8.0 CPUs.
Reviewed-by: Marc Zyngier <redacted>
Signed-off-by: Christoffer Dall <redacted>
---
Notes:
Changes since v3:
- Added BUG() to 32-bit ARM VHE run function
- Omitted QC Falkor BP Hardening functionality from VHE-specific
function
Changes since v2:
- Reworded commit message
Changes since v1:
- Rename kvm_vcpu_run to kvm_vcpu_run_vhe and rename __kvm_vcpu_run to
__kvm_vcpu_run_nvhe
- Removed stray whitespace line
arch/arm/include/asm/kvm_asm.h | 5 ++-
arch/arm/kvm/hyp/switch.c | 2 +-
arch/arm64/include/asm/kvm_asm.h | 4 ++-
arch/arm64/kvm/hyp/switch.c | 66 +++++++++++++++++++++++++++++++++++++++-
virt/kvm/arm/arm.c | 5 ++-
5 files changed, 77 insertions(+), 5 deletions(-)
diff --git a/arch/arm/include/asm/kvm_asm.h b/arch/arm/include/asm/kvm_asm.h
index 36dd2962a42d..5a953ecb0d78 100644
--- a/arch/arm/include/asm/kvm_asm.h
+++ b/arch/arm/include/asm/kvm_asm.h@@ -70,7 +70,10 @@ extern void __kvm_tlb_flush_local_vmid(struct kvm_vcpu *vcpu); extern void __kvm_timer_set_cntvoff(u32 cntvoff_low, u32 cntvoff_high); -extern int __kvm_vcpu_run(struct kvm_vcpu *vcpu); +/* no VHE on 32-bit :( */ +static inline int kvm_vcpu_run_vhe(struct kvm_vcpu *vcpu) { BUG(); return 0; } + +extern int __kvm_vcpu_run_nvhe(struct kvm_vcpu *vcpu); extern void __init_stage2_translation(void);
diff --git a/arch/arm/kvm/hyp/switch.c b/arch/arm/kvm/hyp/switch.c
index e86679daddff..aac025783ee8 100644
--- a/arch/arm/kvm/hyp/switch.c
+++ b/arch/arm/kvm/hyp/switch.c@@ -154,7 +154,7 @@ static bool __hyp_text __populate_fault_info(struct kvm_vcpu *vcpu) return true; } -int __hyp_text __kvm_vcpu_run(struct kvm_vcpu *vcpu) +int __hyp_text __kvm_vcpu_run_nvhe(struct kvm_vcpu *vcpu) { struct kvm_cpu_context *host_ctxt; struct kvm_cpu_context *guest_ctxt;
diff --git a/arch/arm64/include/asm/kvm_asm.h b/arch/arm64/include/asm/kvm_asm.h
index 6b626750b0a1..0be2747a6c5f 100644
--- a/arch/arm64/include/asm/kvm_asm.h
+++ b/arch/arm64/include/asm/kvm_asm.h@@ -58,7 +58,9 @@ extern void __kvm_tlb_flush_local_vmid(struct kvm_vcpu *vcpu); extern void __kvm_timer_set_cntvoff(u32 cntvoff_low, u32 cntvoff_high); -extern int __kvm_vcpu_run(struct kvm_vcpu *vcpu); +extern int kvm_vcpu_run_vhe(struct kvm_vcpu *vcpu); + +extern int __kvm_vcpu_run_nvhe(struct kvm_vcpu *vcpu); extern u64 __vgic_v3_get_ich_vtr_el2(void); extern u64 __vgic_v3_read_vmcr(void);
diff --git a/arch/arm64/kvm/hyp/switch.c b/arch/arm64/kvm/hyp/switch.c
index d2c0b1ae3216..b6126af539b6 100644
--- a/arch/arm64/kvm/hyp/switch.c
+++ b/arch/arm64/kvm/hyp/switch.c@@ -362,7 +362,71 @@ static bool __hyp_text fixup_guest_exit(struct kvm_vcpu *vcpu, u64 *exit_code) return false; } -int __hyp_text __kvm_vcpu_run(struct kvm_vcpu *vcpu) +/* Switch to the guest for VHE systems running in EL2 */ +int kvm_vcpu_run_vhe(struct kvm_vcpu *vcpu) +{ + struct kvm_cpu_context *host_ctxt; + struct kvm_cpu_context *guest_ctxt; + bool fp_enabled; + u64 exit_code; + + vcpu = kern_hyp_va(vcpu); + + host_ctxt = kern_hyp_va(vcpu->arch.host_cpu_context); + host_ctxt->__hyp_running_vcpu = vcpu; + guest_ctxt = &vcpu->arch.ctxt; + + __sysreg_save_host_state(host_ctxt); + + __activate_traps(vcpu); + __activate_vm(vcpu); + + __vgic_restore_state(vcpu); + __timer_enable_traps(vcpu); + + /* + * We must restore the 32-bit state before the sysregs, thanks + * to erratum #852523 (Cortex-A57) or #853709 (Cortex-A72). + */ + __sysreg32_restore_state(vcpu); + __sysreg_restore_guest_state(guest_ctxt); + __debug_switch_to_guest(vcpu); + + do { + /* Jump in the fire! */ + exit_code = __guest_enter(vcpu, host_ctxt); + + /* And we're baaack! */ + } while (fixup_guest_exit(vcpu, &exit_code)); + + fp_enabled = __fpsimd_enabled(); + + __sysreg_save_guest_state(guest_ctxt); + __sysreg32_save_state(vcpu); + __timer_disable_traps(vcpu); + __vgic_save_state(vcpu); + + __deactivate_traps(vcpu); + __deactivate_vm(vcpu); + + __sysreg_restore_host_state(host_ctxt); + + if (fp_enabled) { + __fpsimd_save_state(&guest_ctxt->gp_regs.fp_regs); + __fpsimd_restore_state(&host_ctxt->gp_regs.fp_regs); + } + + /* + * This must come after restoring the host sysregs, since a non-VHE + * system may enable SPE here and make use of the TTBRs. + */ + __debug_switch_to_host(vcpu); + + return exit_code; +} + +/* Switch to the guest for legacy non-VHE systems */ +int __hyp_text __kvm_vcpu_run_nvhe(struct kvm_vcpu *vcpu) { struct kvm_cpu_context *host_ctxt; struct kvm_cpu_context *guest_ctxt;
diff --git a/virt/kvm/arm/arm.c b/virt/kvm/arm/arm.c
index 2062d9357971..5bd879c78951 100644
--- a/virt/kvm/arm/arm.c
+++ b/virt/kvm/arm/arm.c@@ -736,7 +736,10 @@ int kvm_arch_vcpu_ioctl_run(struct kvm_vcpu *vcpu, struct kvm_run *run) if (has_vhe()) kvm_arm_vhe_guest_enter(); - ret = kvm_call_hyp(__kvm_vcpu_run, vcpu); + if (has_vhe()) + ret = kvm_vcpu_run_vhe(vcpu); + else + ret = kvm_call_hyp(__kvm_vcpu_run_nvhe, vcpu); if (has_vhe()) kvm_arm_vhe_guest_exit();
--
2.14.2