On Mon, Jan 14, 2013 at 10:11 AM, Will Deacon <will.deacon@xxxxxxx> wrote: > On Tue, Jan 08, 2013 at 06:39:03PM +0000, Christoffer Dall wrote: >> Sets up KVM code to handle all exceptions taken to Hyp mode. >> >> When the kernel is booted in Hyp mode, calling an hvc instruction with r0 >> pointing to the new vectors, the HVBAR is changed to the the vector pointers. >> This allows subsystems (like KVM here) to execute code in Hyp-mode with the >> MMU disabled. >> >> We initialize other Hyp-mode registers and enables the MMU for Hyp-mode from >> the id-mapped hyp initialization code. Afterwards, the HVBAR is changed to >> point to KVM Hyp vectors used to catch guest faults and to switch to Hyp mode >> to perform a world-switch into a KVM guest. >> >> Also provides memory mapping code to map required code pages, data structures, >> and I/O regions accessed in Hyp mode at the same virtual address as the host >> kernel virtual addresses, but which conforms to the architectural requirements >> for translations in Hyp mode. This interface is added in arch/arm/kvm/arm_mmu.c >> and comprises: >> - create_hyp_mappings(from, to); >> - create_hyp_io_mappings(from, to, phys_addr); >> - free_hyp_pmds(); > > [...] > >> diff --git a/arch/arm/kvm/arm.c b/arch/arm/kvm/arm.c >> index 82cb338..2dddc58 100644 >> --- a/arch/arm/kvm/arm.c >> +++ b/arch/arm/kvm/arm.c >> @@ -34,11 +34,21 @@ >> #include <asm/ptrace.h> >> #include <asm/mman.h> >> #include <asm/cputype.h> >> +#include <asm/tlbflush.h> >> +#include <asm/virt.h> >> +#include <asm/kvm_arm.h> >> +#include <asm/kvm_asm.h> >> +#include <asm/kvm_mmu.h> >> >> #ifdef REQUIRES_VIRT >> __asm__(".arch_extension virt"); >> #endif >> >> +static DEFINE_PER_CPU(unsigned long, kvm_arm_hyp_stack_page); >> +static struct vfp_hard_struct __percpu *kvm_host_vfp_state; >> +static unsigned long hyp_default_vectors; >> + >> + >> int kvm_arch_hardware_enable(void *garbage) >> { >> return 0; >> @@ -336,9 +346,176 @@ long kvm_arch_vm_ioctl(struct file *filp, >> return -EINVAL; >> } >> >> +static void cpu_init_hyp_mode(void *vector) >> +{ >> + unsigned long long pgd_ptr; >> + unsigned long hyp_stack_ptr; >> + unsigned long stack_page; >> + unsigned long vector_ptr; >> + >> + /* Switch from the HYP stub to our own HYP init vector */ >> + __hyp_set_vectors((unsigned long)vector); >> + >> + pgd_ptr = (unsigned long long)kvm_mmu_get_httbr(); >> + stack_page = __get_cpu_var(kvm_arm_hyp_stack_page); >> + hyp_stack_ptr = stack_page + PAGE_SIZE; >> + vector_ptr = (unsigned long)__kvm_hyp_vector; >> + >> + /* >> + * Call initialization code, and switch to the full blown >> + * HYP code. The init code corrupts r12, so set the clobber >> + * list accordingly. >> + */ >> + asm volatile ( >> + "mov r0, %[pgd_ptr_low]\n\t" >> + "mov r1, %[pgd_ptr_high]\n\t" >> + "mov r2, %[hyp_stack_ptr]\n\t" >> + "mov r3, %[vector_ptr]\n\t" >> + "hvc #0\n\t" : : >> + [pgd_ptr_low] "r" ((unsigned long)(pgd_ptr & 0xffffffff)), >> + [pgd_ptr_high] "r" ((unsigned long)(pgd_ptr >> 32ULL)), >> + [hyp_stack_ptr] "r" (hyp_stack_ptr), >> + [vector_ptr] "r" (vector_ptr) : >> + "r0", "r1", "r2", "r3", "r12"); >> +} > > Use kvm_call_hyp here instead. > good idea: commit 00e22196205800ce9caa561e7c806023f4915138 Author: Christoffer Dall <c.dall@xxxxxxxxxxxxxxxxxxxxxx> Date: Mon Jan 14 11:32:36 2013 -0500 KVM: ARM: Reuse kvm_call_hyp in vcpu_init_hyp_mode Instead of directly and manually callin the hypercall into the KVM init code, use the kvm_call_hyp function, which only requires a small abuse of the prototype in exchange for much nicer C code. Cc: Will Deacon <will.deacon@xxxxxxx> Signed-off-by: Christoffer Dall <c.dall@xxxxxxxxxxxxxxxxxxxxxx> diff --git a/arch/arm/kvm/arm.c b/arch/arm/kvm/arm.c index 6997326..b5c6ab1 100644 --- a/arch/arm/kvm/arm.c +++ b/arch/arm/kvm/arm.c @@ -971,6 +971,7 @@ long kvm_arch_vm_ioctl(struct file *filp, static void cpu_init_hyp_mode(void *vector) { unsigned long long pgd_ptr; + unsigned long pgd_low, pgd_high; unsigned long hyp_stack_ptr; unsigned long stack_page; unsigned long vector_ptr; @@ -979,26 +980,20 @@ static void cpu_init_hyp_mode(void *vector) __hyp_set_vectors((unsigned long)vector); pgd_ptr = (unsigned long long)kvm_mmu_get_httbr(); + pgd_low = (pgd_ptr & ((1ULL << 32) - 1)); + pgd_high = (pgd_ptr >> 32ULL); stack_page = __get_cpu_var(kvm_arm_hyp_stack_page); hyp_stack_ptr = stack_page + PAGE_SIZE; vector_ptr = (unsigned long)__kvm_hyp_vector; /* * Call initialization code, and switch to the full blown - * HYP code. The init code corrupts r12, so set the clobber - * list accordingly. + * HYP code. The init code doesn't need to preserve these registers as + * r1-r3 and r12 are already callee save according to the AAPCS. + * Note that we slightly misuse the prototype by casing the pgd_low to + * a void *. */ - asm volatile ( - "mov r0, %[pgd_ptr_low]\n\t" - "mov r1, %[pgd_ptr_high]\n\t" - "mov r2, %[hyp_stack_ptr]\n\t" - "mov r3, %[vector_ptr]\n\t" - "hvc #0\n\t" : : - [pgd_ptr_low] "r" ((unsigned long)(pgd_ptr & 0xffffffff)), - [pgd_ptr_high] "r" ((unsigned long)(pgd_ptr >> 32ULL)), - [hyp_stack_ptr] "r" (hyp_stack_ptr), - [vector_ptr] "r" (vector_ptr) : - "r0", "r1", "r2", "r3", "r12"); + kvm_call_hyp((void *)pgd_low, pgd_high, hyp_stack_ptr, vector_ptr); } /** -- Thanks, -Christoffer -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html