From 280b748e871e5a9bd61fc13019b8cbda6e0242dd Mon Sep 17 00:00:00 2001 From: Jintack Lim Date: Thu, 9 Feb 2023 17:58:18 +0000 Subject: [PATCH] KVM: arm64: nv: Emulate EL12 register accesses from the virtual EL2 With HCR_EL2.NV bit set, accesses to EL12 registers in the virtual EL2 trap to EL2. Handle those traps just like we do for EL1 registers. One exception is CNTKCTL_EL12. We don't trap on CNTKCTL_EL1 for non-VHE virtual EL2 because we don't have to. However, accessing CNTKCTL_EL12 will trap since it's one of the EL12 registers controlled by HCR_EL2.NV bit. Therefore, add a handler for it and don't treat it as a non-trap-registers when preparing a shadow context. These registers, being only a view on their EL1 counterpart, are permanently hidden from userspace. Reviewed-by: Alexandru Elisei Signed-off-by: Jintack Lim [maz: EL12_REG(), register visibility] Signed-off-by: Marc Zyngier Link: https://lore.kernel.org/r/20230209175820.1939006-17-maz@kernel.org Signed-off-by: Oliver Upton --- arch/arm64/kvm/sys_regs.c | 37 +++++++++++++++++++++++++++++++++++++ 1 file changed, 37 insertions(+) diff --git a/arch/arm64/kvm/sys_regs.c b/arch/arm64/kvm/sys_regs.c index 55a14c8..f5dd4f4 100644 --- a/arch/arm64/kvm/sys_regs.c +++ b/arch/arm64/kvm/sys_regs.c @@ -1482,6 +1482,26 @@ static unsigned int el2_visibility(const struct kvm_vcpu *vcpu, .val = v, \ } +/* + * EL{0,1}2 registers are the EL2 view on an EL0 or EL1 register when + * HCR_EL2.E2H==1, and only in the sysreg table for convenience of + * handling traps. Given that, they are always hidden from userspace. + */ +static unsigned int elx2_visibility(const struct kvm_vcpu *vcpu, + const struct sys_reg_desc *rd) +{ + return REG_HIDDEN_USER; +} + +#define EL12_REG(name, acc, rst, v) { \ + SYS_DESC(SYS_##name##_EL12), \ + .access = acc, \ + .reset = rst, \ + .reg = name##_EL1, \ + .val = v, \ + .visibility = elx2_visibility, \ +} + /* sys_reg_desc initialiser for known cpufeature ID registers */ #define ID_SANITISED(name) { \ SYS_DESC(SYS_##name), \ @@ -2031,6 +2051,23 @@ static const struct sys_reg_desc sys_reg_descs[] = { EL2_REG(CNTVOFF_EL2, access_rw, reset_val, 0), EL2_REG(CNTHCTL_EL2, access_rw, reset_val, 0), + EL12_REG(SCTLR, access_vm_reg, reset_val, 0x00C50078), + EL12_REG(CPACR, access_rw, reset_val, 0), + EL12_REG(TTBR0, access_vm_reg, reset_unknown, 0), + EL12_REG(TTBR1, access_vm_reg, reset_unknown, 0), + EL12_REG(TCR, access_vm_reg, reset_val, 0), + { SYS_DESC(SYS_SPSR_EL12), access_spsr}, + { SYS_DESC(SYS_ELR_EL12), access_elr}, + EL12_REG(AFSR0, access_vm_reg, reset_unknown, 0), + EL12_REG(AFSR1, access_vm_reg, reset_unknown, 0), + EL12_REG(ESR, access_vm_reg, reset_unknown, 0), + EL12_REG(FAR, access_vm_reg, reset_unknown, 0), + EL12_REG(MAIR, access_vm_reg, reset_unknown, 0), + EL12_REG(AMAIR, access_vm_reg, reset_amair_el1, 0), + EL12_REG(VBAR, access_rw, reset_val, 0), + EL12_REG(CONTEXTIDR, access_vm_reg, reset_val, 0), + EL12_REG(CNTKCTL, access_rw, reset_val, 0), + EL2_REG(SP_EL2, NULL, reset_unknown, 0), }; -- 2.7.4