On Mon, Dec 11, 2017 at 09:53:13AM +0000, Marc Zyngier wrote:

On 07/12/17 17:06, Christoffer Dall wrote:

quoted

So far this is just a copy of the legacy non-VHE switch function, where
we only change the existing calls to has_vhe() in both the original and
new functions.

I'm not sure I correctly parse the above. Do you want to say that you
use has_vhe() to select the right world switch back-end? Or did you mean
to drop some of the has_vhe() calls in the non-VHE case?

That's a leftover from a previous patch version.  How about the
following instead?

  So far this is just 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.


Thanks,
-Christoffer

quoted

Signed-off-by: Christoffer Dall <redacted>
---

Notes:
    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      | 58 +++++++++++++++++++++++++++++++++++++++-
 virt/kvm/arm/arm.c               |  5 +++-
 5 files changed, 69 insertions(+), 5 deletions(-)

diff --git a/arch/arm/include/asm/kvm_asm.h b/arch/arm/include/asm/kvm_asm.h
index 36dd2962a42d..4ac717276543 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) { 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 c3b9799e2e13..7b2bd25e3b10 100644
--- a/arch/arm/kvm/hyp/switch.c
+++ b/arch/arm/kvm/hyp/switch.c

@@ -153,7 +153,7 @@ 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 33e0edc6f8be..adaf1db12271 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 845e3bece399..8f32f8dcab65 100644
--- a/arch/arm64/kvm/hyp/switch.c
+++ b/arch/arm64/kvm/hyp/switch.c

@@ -342,7 +342,63 @@ 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;
+	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));
+
+	__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);
+
+	/*
+	 * 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 3e10343374a1..104ee524c75a 100644
--- a/virt/kvm/arm/arm.c
+++ b/virt/kvm/arm/arm.c

@@ -712,7 +712,10 @@ int kvm_arch_vcpu_ioctl_run(struct kvm_vcpu *vcpu, struct kvm_run *run)
 		trace_kvm_entry(*vcpu_pc(vcpu));
 		guest_enter_irqoff();
 
-		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);
 
 		vcpu->mode = OUTSIDE_GUEST_MODE;
 		vcpu->stat.exits++;

Otherwise looks good to me.

	M.
-- 
Jazz is not dead. It just smells funny...