[PATCH 23/27] KVM: arm64: nv: Add SVC trap forwarding
Marc Zyngier
maz at kernel.org
Wed Jul 12 07:58:06 PDT 2023
HFGITR_EL2 allows the trap of SVC instructions to EL2. Allow these
traps to be forwarded. Take this opportunity to deny any 32bit activity
when NV is enabled.
Signed-off-by: Marc Zyngier <maz at kernel.org>
---
arch/arm64/kvm/arm.c | 4 ++++
arch/arm64/kvm/handle_exit.c | 12 ++++++++++++
2 files changed, 16 insertions(+)
diff --git a/arch/arm64/kvm/arm.c b/arch/arm64/kvm/arm.c
index c2c14059f6a8..f876e1bbaad2 100644
--- a/arch/arm64/kvm/arm.c
+++ b/arch/arm64/kvm/arm.c
@@ -36,6 +36,7 @@
#include <asm/kvm_arm.h>
#include <asm/kvm_asm.h>
#include <asm/kvm_mmu.h>
+#include <asm/kvm_nested.h>
#include <asm/kvm_pkvm.h>
#include <asm/kvm_emulate.h>
#include <asm/sections.h>
@@ -811,6 +812,9 @@ static bool vcpu_mode_is_bad_32bit(struct kvm_vcpu *vcpu)
if (likely(!vcpu_mode_is_32bit(vcpu)))
return false;
+ if (vcpu_has_nv(vcpu))
+ return true;
+
return !kvm_supports_32bit_el0();
}
diff --git a/arch/arm64/kvm/handle_exit.c b/arch/arm64/kvm/handle_exit.c
index 6dcd6604b6bc..3b86d534b995 100644
--- a/arch/arm64/kvm/handle_exit.c
+++ b/arch/arm64/kvm/handle_exit.c
@@ -226,6 +226,17 @@ static int kvm_handle_eret(struct kvm_vcpu *vcpu)
return 1;
}
+static int handle_svc(struct kvm_vcpu *vcpu)
+{
+ /*
+ * So far, SVC traps only for NV via HFGITR_EL2. A SVC from a
+ * 32bit guest would be caught by vpcu_mode_is_bad_32bit(), so
+ * we should only have to deal with a 64 bit exception.
+ */
+ kvm_inject_nested_sync(vcpu, kvm_vcpu_get_esr(vcpu));
+ return 1;
+}
+
static exit_handle_fn arm_exit_handlers[] = {
[0 ... ESR_ELx_EC_MAX] = kvm_handle_unknown_ec,
[ESR_ELx_EC_WFx] = kvm_handle_wfx,
@@ -239,6 +250,7 @@ static exit_handle_fn arm_exit_handlers[] = {
[ESR_ELx_EC_SMC32] = handle_smc,
[ESR_ELx_EC_HVC64] = handle_hvc,
[ESR_ELx_EC_SMC64] = handle_smc,
+ [ESR_ELx_EC_SVC64] = handle_svc,
[ESR_ELx_EC_SYS64] = kvm_handle_sys_reg,
[ESR_ELx_EC_SVE] = handle_sve,
[ESR_ELx_EC_ERET] = kvm_handle_eret,
--
2.34.1
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