From: Marc Zyngier When running an EL2 guest, we need to make sure we don't sample SCTLR_EL1 to work out the virtio endianness, as this is likely to be a bit random. Signed-off-by: Marc Zyngier Signed-off-by: Andre Przywara --- arm64/include/kvm/kvm-cpu-arch.h | 5 ++-- arm64/kvm-cpu.c | 47 +++++++++++++++++++++++++------- 2 files changed, 40 insertions(+), 12 deletions(-) diff --git a/arm64/include/kvm/kvm-cpu-arch.h b/arm64/include/kvm/kvm-cpu-arch.h index 1af394aa3..85646ad4c 100644 --- a/arm64/include/kvm/kvm-cpu-arch.h +++ b/arm64/include/kvm/kvm-cpu-arch.h @@ -10,8 +10,9 @@ #define ARM_MPIDR_HWID_BITMASK 0xFF00FFFFFFUL #define ARM_CPU_ID 3, 0, 0, 0 #define ARM_CPU_ID_MPIDR 5 -#define ARM_CPU_CTRL 3, 0, 1, 0 -#define ARM_CPU_CTRL_SCTLR_EL1 0 +#define SYS_SCTLR_EL1 3, 4, 1, 0, 0 +#define SYS_SCTLR_EL2 3, 4, 1, 0, 0 +#define SYS_HCR_EL2 3, 4, 1, 1, 0 struct kvm_cpu { pthread_t thread; diff --git a/arm64/kvm-cpu.c b/arm64/kvm-cpu.c index 5e4f3a7dd..35e1c6396 100644 --- a/arm64/kvm-cpu.c +++ b/arm64/kvm-cpu.c @@ -12,6 +12,7 @@ #define SCTLR_EL1_E0E_MASK (1 << 24) #define SCTLR_EL1_EE_MASK (1 << 25) +#define HCR_EL2_TGE (1 << 27) static int debug_fd; @@ -408,7 +409,8 @@ int kvm_cpu__get_endianness(struct kvm_cpu *vcpu) { struct kvm_one_reg reg; u64 psr; - u64 sctlr; + u64 sctlr, bit; + u64 hcr = 0; /* * Quoting the definition given by Peter Maydell: @@ -419,8 +421,9 @@ int kvm_cpu__get_endianness(struct kvm_cpu *vcpu) * We first check for an AArch32 guest: its endianness can * change when using SETEND, which affects the CPSR.E bit. * - * If we're AArch64, use SCTLR_EL1.E0E if access comes from - * EL0, and SCTLR_EL1.EE if access comes from EL1. + * If we're AArch64, determine which SCTLR register to use, + * depending on NV being used or not. Then use either the E0E + * bit for EL0, or the EE bit for EL1/EL2. */ reg.id = ARM64_CORE_REG(regs.pstate); reg.addr = (u64)&psr; @@ -430,16 +433,40 @@ int kvm_cpu__get_endianness(struct kvm_cpu *vcpu) if (psr & PSR_MODE32_BIT) return (psr & COMPAT_PSR_E_BIT) ? VIRTIO_ENDIAN_BE : VIRTIO_ENDIAN_LE; - reg.id = ARM64_SYS_REG(ARM_CPU_CTRL, ARM_CPU_CTRL_SCTLR_EL1); + if (vcpu->kvm->cfg.arch.nested_virt) { + reg.id = ARM64_SYS_REG(SYS_HCR_EL2); + reg.addr = (u64)&hcr; + if (ioctl(vcpu->vcpu_fd, KVM_GET_ONE_REG, ®) < 0) + die("KVM_GET_ONE_REG failed (HCR_EL2)"); + } + + switch (psr & PSR_MODE_MASK) { + case PSR_MODE_EL0t: + if (hcr & HCR_EL2_TGE) + reg.id = ARM64_SYS_REG(SYS_SCTLR_EL2); + else + reg.id = ARM64_SYS_REG(SYS_SCTLR_EL1); + bit = SCTLR_EL1_E0E_MASK; + break; + case PSR_MODE_EL1t: + case PSR_MODE_EL1h: + reg.id = ARM64_SYS_REG(SYS_SCTLR_EL1); + bit = SCTLR_EL1_EE_MASK; + break; + case PSR_MODE_EL2t: + case PSR_MODE_EL2h: + reg.id = ARM64_SYS_REG(SYS_SCTLR_EL2); + bit = SCTLR_EL1_EE_MASK; + break; + default: + die("What's that mode???\n"); + } + reg.addr = (u64)&sctlr; if (ioctl(vcpu->vcpu_fd, KVM_GET_ONE_REG, ®) < 0) - die("KVM_GET_ONE_REG failed (SCTLR_EL1)"); + die("KVM_GET_ONE_REG failed (SCTLR_ELx)"); - if ((psr & PSR_MODE_MASK) == PSR_MODE_EL0t) - sctlr &= SCTLR_EL1_E0E_MASK; - else - sctlr &= SCTLR_EL1_EE_MASK; - return sctlr ? VIRTIO_ENDIAN_BE : VIRTIO_ENDIAN_LE; + return (sctlr & bit) ? VIRTIO_ENDIAN_BE : VIRTIO_ENDIAN_LE; } void kvm_cpu__show_code(struct kvm_cpu *vcpu) -- 2.25.1