From 6d89d2d9b5bac9dbe40ee106ceda9307b6265234 Mon Sep 17 00:00:00 2001 From: Marc Zyngier Date: Tue, 12 Feb 2013 12:40:22 +0000 Subject: arm/arm64: KVM: MMIO support for BE guest Do the necessary byteswap when host and guest have different views of the universe. Actually, the only case we need to take care of is when the guest is BE. All the other cases are naturally handled. Also be careful about endianness when the data is being memcopy-ed from/to the run buffer. Acked-by: Christoffer Dall Signed-off-by: Marc Zyngier --- arch/arm/kvm/mmio.c | 86 ++++++++++++++++++++++++++++++++++++++++++++++------- 1 file changed, 75 insertions(+), 11 deletions(-) (limited to 'arch/arm/kvm') diff --git a/arch/arm/kvm/mmio.c b/arch/arm/kvm/mmio.c index 0c25d9487d53..4cb5a93182e9 100644 --- a/arch/arm/kvm/mmio.c +++ b/arch/arm/kvm/mmio.c @@ -23,6 +23,68 @@ #include "trace.h" +static void mmio_write_buf(char *buf, unsigned int len, unsigned long data) +{ + void *datap = NULL; + union { + u8 byte; + u16 hword; + u32 word; + u64 dword; + } tmp; + + switch (len) { + case 1: + tmp.byte = data; + datap = &tmp.byte; + break; + case 2: + tmp.hword = data; + datap = &tmp.hword; + break; + case 4: + tmp.word = data; + datap = &tmp.word; + break; + case 8: + tmp.dword = data; + datap = &tmp.dword; + break; + } + + memcpy(buf, datap, len); +} + +static unsigned long mmio_read_buf(char *buf, unsigned int len) +{ + unsigned long data = 0; + union { + u16 hword; + u32 word; + u64 dword; + } tmp; + + switch (len) { + case 1: + data = buf[0]; + break; + case 2: + memcpy(&tmp.hword, buf, len); + data = tmp.hword; + break; + case 4: + memcpy(&tmp.word, buf, len); + data = tmp.word; + break; + case 8: + memcpy(&tmp.dword, buf, len); + data = tmp.dword; + break; + } + + return data; +} + /** * kvm_handle_mmio_return -- Handle MMIO loads after user space emulation * @vcpu: The VCPU pointer @@ -33,28 +95,27 @@ */ int kvm_handle_mmio_return(struct kvm_vcpu *vcpu, struct kvm_run *run) { - unsigned long *dest; + unsigned long data; unsigned int len; int mask; if (!run->mmio.is_write) { - dest = vcpu_reg(vcpu, vcpu->arch.mmio_decode.rt); - *dest = 0; - len = run->mmio.len; if (len > sizeof(unsigned long)) return -EINVAL; - memcpy(dest, run->mmio.data, len); - - trace_kvm_mmio(KVM_TRACE_MMIO_READ, len, run->mmio.phys_addr, - *((u64 *)run->mmio.data)); + data = mmio_read_buf(run->mmio.data, len); if (vcpu->arch.mmio_decode.sign_extend && len < sizeof(unsigned long)) { mask = 1U << ((len * 8) - 1); - *dest = (*dest ^ mask) - mask; + data = (data ^ mask) - mask; } + + trace_kvm_mmio(KVM_TRACE_MMIO_READ, len, run->mmio.phys_addr, + data); + data = vcpu_data_host_to_guest(vcpu, data, len); + *vcpu_reg(vcpu, vcpu->arch.mmio_decode.rt) = data; } return 0; @@ -105,6 +166,7 @@ int io_mem_abort(struct kvm_vcpu *vcpu, struct kvm_run *run, phys_addr_t fault_ipa) { struct kvm_exit_mmio mmio; + unsigned long data; unsigned long rt; int ret; @@ -125,13 +187,15 @@ int io_mem_abort(struct kvm_vcpu *vcpu, struct kvm_run *run, } rt = vcpu->arch.mmio_decode.rt; + data = vcpu_data_guest_to_host(vcpu, *vcpu_reg(vcpu, rt), mmio.len); + trace_kvm_mmio((mmio.is_write) ? KVM_TRACE_MMIO_WRITE : KVM_TRACE_MMIO_READ_UNSATISFIED, mmio.len, fault_ipa, - (mmio.is_write) ? *vcpu_reg(vcpu, rt) : 0); + (mmio.is_write) ? data : 0); if (mmio.is_write) - memcpy(mmio.data, vcpu_reg(vcpu, rt), mmio.len); + mmio_write_buf(mmio.data, mmio.len, data); if (vgic_handle_mmio(vcpu, run, &mmio)) return 1; -- cgit v1.2.3 From ce94fe93d566bf381c6ecbd45010d36c5f04d692 Mon Sep 17 00:00:00 2001 From: Marc Zyngier Date: Tue, 5 Nov 2013 14:12:15 +0000 Subject: arm/arm64: KVM: PSCI: propagate caller endianness to the incoming vcpu When booting a vcpu using PSCI, make sure we start it with the endianness of the caller. Otherwise, secondaries can be pretty unhappy to execute a BE kernel in LE mode... This conforms to PSCI spec Rev B, 5.13.3. Acked-by: Christoffer Dall Signed-off-by: Marc Zyngier --- arch/arm/include/asm/kvm_emulate.h | 5 +++++ arch/arm/kvm/psci.c | 4 ++++ arch/arm64/include/asm/kvm_emulate.h | 8 ++++++++ 3 files changed, 17 insertions(+) (limited to 'arch/arm/kvm') diff --git a/arch/arm/include/asm/kvm_emulate.h b/arch/arm/include/asm/kvm_emulate.h index 8a6be05a46d7..e844b335e33a 100644 --- a/arch/arm/include/asm/kvm_emulate.h +++ b/arch/arm/include/asm/kvm_emulate.h @@ -157,6 +157,11 @@ static inline u32 kvm_vcpu_hvc_get_imm(struct kvm_vcpu *vcpu) return kvm_vcpu_get_hsr(vcpu) & HSR_HVC_IMM_MASK; } +static inline void kvm_vcpu_set_be(struct kvm_vcpu *vcpu) +{ + *vcpu_cpsr(vcpu) |= PSR_E_BIT; +} + static inline bool kvm_vcpu_is_be(struct kvm_vcpu *vcpu) { return !!(*vcpu_cpsr(vcpu) & PSR_E_BIT); diff --git a/arch/arm/kvm/psci.c b/arch/arm/kvm/psci.c index 86a693a02ba3..ae0e06b6a492 100644 --- a/arch/arm/kvm/psci.c +++ b/arch/arm/kvm/psci.c @@ -62,6 +62,10 @@ static unsigned long kvm_psci_vcpu_on(struct kvm_vcpu *source_vcpu) vcpu_set_thumb(vcpu); } + /* Propagate caller endianness */ + if (kvm_vcpu_is_be(source_vcpu)) + kvm_vcpu_set_be(vcpu); + *vcpu_pc(vcpu) = target_pc; vcpu->arch.pause = false; smp_mb(); /* Make sure the above is visible */ diff --git a/arch/arm64/include/asm/kvm_emulate.h b/arch/arm64/include/asm/kvm_emulate.h index b016577e37a4..db805092698c 100644 --- a/arch/arm64/include/asm/kvm_emulate.h +++ b/arch/arm64/include/asm/kvm_emulate.h @@ -177,6 +177,14 @@ static inline u8 kvm_vcpu_trap_get_fault(const struct kvm_vcpu *vcpu) return kvm_vcpu_get_hsr(vcpu) & ESR_EL2_FSC_TYPE; } +static inline void kvm_vcpu_set_be(struct kvm_vcpu *vcpu) +{ + if (vcpu_mode_is_32bit(vcpu)) + *vcpu_cpsr(vcpu) |= COMPAT_PSR_E_BIT; + else + vcpu_sys_reg(vcpu, SCTLR_EL1) |= (1 << 25); +} + static inline bool kvm_vcpu_is_be(struct kvm_vcpu *vcpu) { if (vcpu_mode_is_32bit(vcpu)) -- cgit v1.2.3