[PATCH v6 10/64] KVM: arm64: nv: Inject HVC exceptions to the virtual EL2

Marc Zyngier
2022-01-28T12:28:18Z

From: Jintack Lim <jintack.lim@linaro.org>

As we expect all PSCI calls from the L1 hypervisor to be performed
using SMC when nested virtualization is enabled, it is clear that
all HVC instruction from the VM (including from the virtual EL2)
are supposed to handled in the virtual EL2.

Forward these to EL2 as required.

Reviewed-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>
Reviewed-by: Alexandru Elisei <alexandru.elisei@arm.com>
Signed-off-by: Jintack Lim <jintack.lim@linaro.org>
[maz: add handling of HCR_EL2.HCD]
Signed-off-by: Marc Zyngier <maz@kernel.org>
---
arch/arm64/kvm/handle_exit.c | 11 +++++++++++
1 file changed, 11 insertions(+)

diff --git a/arch/arm64/kvm/handle_exit.c b/arch/arm64/kvm/handle_exit.c
index fd2dd26caf91..6bfb5c31cad1 100644
--- a/arch/arm64/kvm/handle_exit.c
+++ b/arch/arm64/kvm/handle_exit.c
@@ -16,6 +16,7 @@
#include <asm/kvm_asm.h>
#include <asm/kvm_emulate.h>
#include <asm/kvm_mmu.h>
+#include <asm/kvm_nested.h>
#include <asm/debug-monitors.h>
#include <asm/traps.h>

@@ -40,6 +41,16 @@ static int handle_hvc(struct kvm_vcpu *vcpu)
kvm_vcpu_hvc_get_imm(vcpu));
vcpu->stat.hvc_exit_stat++;

+ /* Forward hvc instructions to the virtual EL2 if the guest has EL2. */
+ if (vcpu_has_nv(vcpu)) {
+ if (vcpu_read_sys_reg(vcpu, HCR_EL2) & HCR_HCD)
+ kvm_inject_undefined(vcpu);
+ else
+ kvm_inject_nested_sync(vcpu, kvm_vcpu_get_esr(vcpu));
+
+ return 1;
+ }
+
ret = kvm_hvc_call_handler(vcpu);
if (ret < 0) {
vcpu_set_reg(vcpu, 0, ~0UL);