From: Christoffer Dall <christoffer.dall@xxxxxxxxxx>
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 <marc.zyngier@xxxxxxx>
Signed-off-by: Christoffer Dall <christoffer.dall@xxxxxxxxxx>
Signed-off-by: Marc Zyngier <marc.zyngier@xxxxxxx>
---
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/include/asm/kvm_host.h | 7 +++++
arch/arm64/kvm/hyp/switch.c | 66 ++++++++++++++++++++++++++++++++++++++-
virt/kvm/arm/arm.c | 12 ++++---
6 files changed, 87 insertions(+), 9 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 7149f1520382..d53d40704416 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/include/asm/kvm_host.h b/arch/arm64/include/asm/kvm_host.h
index c30fc96992df..87abc94fb591 100644
--- a/arch/arm64/include/asm/kvm_host.h
+++ b/arch/arm64/include/asm/kvm_host.h
@@ -428,6 +428,13 @@ static inline void kvm_arm_vhe_guest_enter(void)
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)
diff --git a/arch/arm64/kvm/hyp/switch.c b/arch/arm64/kvm/hyp/switch.c
index b055111df1a1..1b94ac6a85e6 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..09dbee56ed8f 100644
--- a/virt/kvm/arm/arm.c
+++ b/virt/kvm/arm/arm.c
@@ -733,13 +733,15 @@ int kvm_arch_vcpu_ioctl_run(struct kvm_vcpu *vcpu, struct kvm_run *run)
*/
trace_kvm_entry(*vcpu_pc(vcpu));
guest_enter_irqoff();
- if (has_vhe())
- kvm_arm_vhe_guest_enter();
-
- ret = kvm_call_hyp(__kvm_vcpu_run, vcpu);
- if (has_vhe())
+ if (has_vhe()) {
+ kvm_arm_vhe_guest_enter();
+ ret = kvm_vcpu_run_vhe(vcpu);
kvm_arm_vhe_guest_exit();
+ } else {
+ ret = kvm_call_hyp(__kvm_vcpu_run_nvhe, vcpu);
+ }
+
vcpu->mode = OUTSIDE_GUEST_MODE;
vcpu->stat.exits++;
/*
--
2.14.2
