Re: [PATCH v6 19/64] KVM: arm64: nv: Trap SPSR_EL1, ELR_EL1 and VBAR_EL1 from virtual EL2
From: Alexandru Elisei <hidden>
Date: 2022-02-03 17:32:02
Also in:
kvm, kvmarm
The previous patch: "KVM: arm64: nv: Trap EL1 VM register accesses in virtual EL2" -> sets the trap bits to trap EL1 VM registers. This patch: "KVM: arm64: nv: Trap SPSR_EL1, ELR_EL1 and VBAR_EL1 from virtual EL2" -> does not set the trap bits to trap the registers. Might be worth changing the subject to something like "Add accessors for <register list here>" to reflect what the patch does. Other than that, the patch looks good to me. Thanks, Alex On Fri, Jan 28, 2022 at 12:18:27PM +0000, Marc Zyngier wrote:
quoted hunk ↗ jump to hunk
From: Jintack Lim <redacted> 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 <redacted> 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 9d3520f1d17a..4f2bcc1e0c25 100644 --- a/arch/arm64/kvm/sys_regs.c +++ b/arch/arm64/kvm/sys_regs.c@@ -1650,6 +1650,30 @@ 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)@@ -1812,6 +1836,9 @@ 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 },@@ -1859,7 +1886,7 @@ 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 },-- 2.30.2
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