| Message ID | 1399541568-13803-10-git-send-email-marc.zyngier@arm.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On 8 May 2014 10:32, Marc Zyngier <marc.zyngier@arm.com> wrote: > +int kvm_cpu__get_endianness(struct kvm_cpu *vcpu) > +{ > + struct kvm_one_reg reg; > + u64 psr; > + u64 sctlr; > + > + /* > + * Quoting the definition given by Peter Maydell: > + * > + * "Endianness of the CPU which does the virtio reset at the > + * point when it does that reset" > + * > + * 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. > + */ I note that the set of checks described here match the logic of the ARM ARM BigEndian() pseudocode function, which is a good sign. thanks -- PMM -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On 08/05/14 11:06, Peter Maydell wrote: > On 8 May 2014 10:32, Marc Zyngier <marc.zyngier@arm.com> wrote: >> +int kvm_cpu__get_endianness(struct kvm_cpu *vcpu) >> +{ >> + struct kvm_one_reg reg; >> + u64 psr; >> + u64 sctlr; >> + >> + /* >> + * Quoting the definition given by Peter Maydell: >> + * >> + * "Endianness of the CPU which does the virtio reset at the >> + * point when it does that reset" >> + * >> + * 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. >> + */ > > I note that the set of checks described here match the logic > of the ARM ARM BigEndian() pseudocode function, which is > a good sign. Pure luck. Or maybe I'm now going slightly mad. Either way, consistency is good... ;-) Thanks, M.
On Thu, May 08, 2014 at 10:32:48AM +0100, Marc Zyngier wrote: > Implement the kvm_cpu__get_endianness call for both AArch32 and > AArch64, and advertise the bi-endianness support. > > Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> Acked-by: Will Deacon <will.deacon@arm.com> Will -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/tools/kvm/arm/aarch32/kvm-cpu.c b/tools/kvm/arm/aarch32/kvm-cpu.c index bd71037..464b473 100644 --- a/tools/kvm/arm/aarch32/kvm-cpu.c +++ b/tools/kvm/arm/aarch32/kvm-cpu.c @@ -1,5 +1,6 @@ #include "kvm/kvm-cpu.h" #include "kvm/kvm.h" +#include "kvm/virtio.h" #include <asm/ptrace.h> @@ -76,6 +77,19 @@ void kvm_cpu__reset_vcpu(struct kvm_cpu *vcpu) die_perror("KVM_SET_ONE_REG failed (pc)"); } +int kvm_cpu__get_endianness(struct kvm_cpu *vcpu) +{ + struct kvm_one_reg reg; + u32 data; + + reg.id = ARM_CORE_REG(usr_regs.ARM_cpsr); + reg.addr = (u64)(unsigned long)&data; + if (ioctl(vcpu->vcpu_fd, KVM_GET_ONE_REG, ®) < 0) + die("KVM_GET_ONE_REG failed (cpsr)"); + + return (data & PSR_E_BIT) ? VIRTIO_ENDIAN_BE : VIRTIO_ENDIAN_LE; +} + void kvm_cpu__show_code(struct kvm_cpu *vcpu) { struct kvm_one_reg reg; diff --git a/tools/kvm/arm/aarch64/include/kvm/kvm-cpu-arch.h b/tools/kvm/arm/aarch64/include/kvm/kvm-cpu-arch.h index 7d70c3b..2ffa7ad 100644 --- a/tools/kvm/arm/aarch64/include/kvm/kvm-cpu-arch.h +++ b/tools/kvm/arm/aarch64/include/kvm/kvm-cpu-arch.h @@ -13,5 +13,7 @@ #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 #endif /* KVM__KVM_CPU_ARCH_H */ diff --git a/tools/kvm/arm/aarch64/kvm-cpu.c b/tools/kvm/arm/aarch64/kvm-cpu.c index 059e42c..71a2a3a 100644 --- a/tools/kvm/arm/aarch64/kvm-cpu.c +++ b/tools/kvm/arm/aarch64/kvm-cpu.c @@ -1,12 +1,17 @@ #include "kvm/kvm-cpu.h" #include "kvm/kvm.h" +#include "kvm/virtio.h" #include <asm/ptrace.h> #define COMPAT_PSR_F_BIT 0x00000040 #define COMPAT_PSR_I_BIT 0x00000080 +#define COMPAT_PSR_E_BIT 0x00000200 #define COMPAT_PSR_MODE_SVC 0x00000013 +#define SCTLR_EL1_E0E_MASK (1 << 24) +#define SCTLR_EL1_EE_MASK (1 << 25) + #define ARM64_CORE_REG(x) (KVM_REG_ARM64 | KVM_REG_SIZE_U64 | \ KVM_REG_ARM_CORE | KVM_REG_ARM_CORE_REG(x)) @@ -133,6 +138,44 @@ void kvm_cpu__reset_vcpu(struct kvm_cpu *vcpu) return reset_vcpu_aarch64(vcpu); } +int kvm_cpu__get_endianness(struct kvm_cpu *vcpu) +{ + struct kvm_one_reg reg; + u64 psr; + u64 sctlr; + + /* + * Quoting the definition given by Peter Maydell: + * + * "Endianness of the CPU which does the virtio reset at the + * point when it does that reset" + * + * 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. + */ + reg.id = ARM64_CORE_REG(regs.pstate); + reg.addr = (u64)&psr; + if (ioctl(vcpu->vcpu_fd, KVM_GET_ONE_REG, ®) < 0) + die("KVM_GET_ONE_REG failed (spsr[EL1])"); + + 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); + reg.addr = (u64)&sctlr; + if (ioctl(vcpu->vcpu_fd, KVM_GET_ONE_REG, ®) < 0) + die("KVM_GET_ONE_REG failed (SCTLR_EL1)"); + + 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; +} + void kvm_cpu__show_code(struct kvm_cpu *vcpu) { struct kvm_one_reg reg; diff --git a/tools/kvm/arm/include/arm-common/kvm-arch.h b/tools/kvm/arm/include/arm-common/kvm-arch.h index b6c4bf8..5d2fab2 100644 --- a/tools/kvm/arm/include/arm-common/kvm-arch.h +++ b/tools/kvm/arm/include/arm-common/kvm-arch.h @@ -35,6 +35,8 @@ #define VIRTIO_DEFAULT_TRANS(kvm) \ ((kvm)->cfg.arch.virtio_trans_pci ? VIRTIO_PCI : VIRTIO_MMIO) +#define VIRTIO_RING_ENDIAN (VIRTIO_ENDIAN_LE | VIRTIO_ENDIAN_BE) + static inline bool arm_addr_in_ioport_region(u64 phys_addr) { u64 limit = KVM_IOPORT_AREA + ARM_IOPORT_SIZE;
Implement the kvm_cpu__get_endianness call for both AArch32 and AArch64, and advertise the bi-endianness support. Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> --- tools/kvm/arm/aarch32/kvm-cpu.c | 14 ++++++++ tools/kvm/arm/aarch64/include/kvm/kvm-cpu-arch.h | 2 ++ tools/kvm/arm/aarch64/kvm-cpu.c | 43 ++++++++++++++++++++++++ tools/kvm/arm/include/arm-common/kvm-arch.h | 2 ++ 4 files changed, 61 insertions(+)