[PATCH v3 19/66] KVM: arm64: nv: Trap SPSR_EL1, ELR_EL1 and VBAR_EL1 from virtual EL2

Marc Zyngier
2020-12-10T16:22:42Z

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

For the same reason we trap virtual memory register accesses at virtual
EL2, we need to trap SPSR_EL1, ELR_EL1 and VBAR_EL1 accesses. ARM v8.3
introduces the HCR_EL2.NV1 bit to be able to trap on those register
accesses in EL1. Do not set this bit until the whole nesting support is
completed.

Signed-off-by: Jintack Lim <jintack.lim@linaro.org>
Signed-off-by: Marc Zyngier <maz@kernel.org>
---
arch/arm64/kvm/sys_regs.c | 29 ++++++++++++++++++++++++++++-
1 file changed, 28 insertions(+), 1 deletion(-)

diff --git a/arch/arm64/kvm/sys_regs.c b/arch/arm64/kvm/sys_regs.c
index 540a7faaaee3..5185f148f25e 100644
--- a/arch/arm64/kvm/sys_regs.c
+++ b/arch/arm64/kvm/sys_regs.c
@@ -1567,6 +1567,30 @@ static bool access_sp_el1(struct kvm_vcpu *vcpu,
return true;
}

+static bool access_elr(struct kvm_vcpu *vcpu,
+ struct sys_reg_params *p,
+ const struct sys_reg_desc *r)
+{
+ if (p->is_write)
+ vcpu_write_sys_reg(vcpu, p->regval, ELR_EL1);
+ else
+ p->regval = vcpu_read_sys_reg(vcpu, ELR_EL1);
+
+ return true;
+}
+
+static bool access_spsr(struct kvm_vcpu *vcpu,
+ struct sys_reg_params *p,
+ const struct sys_reg_desc *r)
+{
+ if (p->is_write)
+ __vcpu_sys_reg(vcpu, SPSR_EL1) = p->regval;
+ else
+ p->regval = __vcpu_sys_reg(vcpu, SPSR_EL1);
+
+ return true;
+}
+
static bool access_spsr_el2(struct kvm_vcpu *vcpu,
struct sys_reg_params *p,
const struct sys_reg_desc *r)
@@ -1728,6 +1752,9 @@ static const struct sys_reg_desc sys_reg_descs[] = {
PTRAUTH_KEY(APDB),
PTRAUTH_KEY(APGA),

+ { SYS_DESC(SYS_SPSR_EL1), access_spsr},
+ { SYS_DESC(SYS_ELR_EL1), access_elr},
+
{ SYS_DESC(SYS_AFSR0_EL1), access_vm_reg, reset_unknown, AFSR0_EL1 },
{ SYS_DESC(SYS_AFSR1_EL1), access_vm_reg, reset_unknown, AFSR1_EL1 },
{ SYS_DESC(SYS_ESR_EL1), access_vm_reg, reset_unknown, ESR_EL1 },
@@ -1759,7 +1786,7 @@ static const struct sys_reg_desc sys_reg_descs[] = {
{ SYS_DESC(SYS_LORC_EL1), trap_loregion },
{ SYS_DESC(SYS_LORID_EL1), trap_loregion },

- { SYS_DESC(SYS_VBAR_EL1), NULL, reset_val, VBAR_EL1, 0 },
+ { SYS_DESC(SYS_VBAR_EL1), access_rw, reset_val, VBAR_EL1, 0 },
{ SYS_DESC(SYS_DISR_EL1), NULL, reset_val, DISR_EL1, 0 },

{ SYS_DESC(SYS_ICC_IAR0_EL1), write_to_read_only },
--
2.29.2