diff options
Diffstat (limited to 'arch/arm/kvm')
| -rw-r--r-- | arch/arm/kvm/arm.c | 172 | ||||
| -rw-r--r-- | arch/arm/kvm/init.S | 95 | ||||
| -rw-r--r-- | arch/arm/kvm/interrupts.S | 62 | ||||
| -rw-r--r-- | arch/arm/kvm/mmu.c | 248 |
4 files changed, 577 insertions, 0 deletions
diff --git a/arch/arm/kvm/arm.c b/arch/arm/kvm/arm.c index d3506b4001a..2c6b780e78a 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; @@ -331,9 +341,171 @@ 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 pgd_low, pgd_high; + 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(); + 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 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 *. + */ + kvm_call_hyp((void *)pgd_low, pgd_high, hyp_stack_ptr, vector_ptr); +} + +/** + * Inits Hyp-mode on all online CPUs + */ +static int init_hyp_mode(void) +{ + phys_addr_t init_phys_addr; + int cpu; + int err = 0; + + /* + * Allocate Hyp PGD and setup Hyp identity mapping + */ + err = kvm_mmu_init(); + if (err) + goto out_err; + + /* + * It is probably enough to obtain the default on one + * CPU. It's unlikely to be different on the others. + */ + hyp_default_vectors = __hyp_get_vectors(); + + /* + * Allocate stack pages for Hypervisor-mode + */ + for_each_possible_cpu(cpu) { + unsigned long stack_page; + + stack_page = __get_free_page(GFP_KERNEL); + if (!stack_page) { + err = -ENOMEM; + goto out_free_stack_pages; + } + + per_cpu(kvm_arm_hyp_stack_page, cpu) = stack_page; + } + + /* + * Execute the init code on each CPU. + * + * Note: The stack is not mapped yet, so don't do anything else than + * initializing the hypervisor mode on each CPU using a local stack + * space for temporary storage. + */ + init_phys_addr = virt_to_phys(__kvm_hyp_init); + for_each_online_cpu(cpu) { + smp_call_function_single(cpu, cpu_init_hyp_mode, + (void *)(long)init_phys_addr, 1); + } + + /* + * Unmap the identity mapping + */ + kvm_clear_hyp_idmap(); + + /* + * Map the Hyp-code called directly from the host + */ + err = create_hyp_mappings(__kvm_hyp_code_start, __kvm_hyp_code_end); + if (err) { + kvm_err("Cannot map world-switch code\n"); + goto out_free_mappings; + } + + /* + * Map the Hyp stack pages + */ + for_each_possible_cpu(cpu) { + char *stack_page = (char *)per_cpu(kvm_arm_hyp_stack_page, cpu); + err = create_hyp_mappings(stack_page, stack_page + PAGE_SIZE); + + if (err) { + kvm_err("Cannot map hyp stack\n"); + goto out_free_mappings; + } + } + + /* + * Map the host VFP structures + */ + kvm_host_vfp_state = alloc_percpu(struct vfp_hard_struct); + if (!kvm_host_vfp_state) { + err = -ENOMEM; + kvm_err("Cannot allocate host VFP state\n"); + goto out_free_mappings; + } + + for_each_possible_cpu(cpu) { + struct vfp_hard_struct *vfp; + + vfp = per_cpu_ptr(kvm_host_vfp_state, cpu); + err = create_hyp_mappings(vfp, vfp + 1); + + if (err) { + kvm_err("Cannot map host VFP state: %d\n", err); + goto out_free_vfp; + } + } + + kvm_info("Hyp mode initialized successfully\n"); + return 0; +out_free_vfp: + free_percpu(kvm_host_vfp_state); +out_free_mappings: + free_hyp_pmds(); +out_free_stack_pages: + for_each_possible_cpu(cpu) + free_page(per_cpu(kvm_arm_hyp_stack_page, cpu)); +out_err: + kvm_err("error initializing Hyp mode: %d\n", err); + return err; +} + +/** + * Initialize Hyp-mode and memory mappings on all CPUs. + */ int kvm_arch_init(void *opaque) { + int err; + + if (!is_hyp_mode_available()) { + kvm_err("HYP mode not available\n"); + return -ENODEV; + } + + if (kvm_target_cpu() < 0) { + kvm_err("Target CPU not supported!\n"); + return -ENODEV; + } + + err = init_hyp_mode(); + if (err) + goto out_err; + return 0; +out_err: + return err; } /* NOP: Compiling as a module not supported */ diff --git a/arch/arm/kvm/init.S b/arch/arm/kvm/init.S index 1dc8926e26d..9f37a79b880 100644 --- a/arch/arm/kvm/init.S +++ b/arch/arm/kvm/init.S @@ -15,5 +15,100 @@ * along with this program; if not, write to the Free Software * Foundation, 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA. */ + +#include <linux/linkage.h> +#include <asm/unified.h> #include <asm/asm-offsets.h> #include <asm/kvm_asm.h> +#include <asm/kvm_arm.h> + +/******************************************************************** + * Hypervisor initialization + * - should be called with: + * r0,r1 = Hypervisor pgd pointer + * r2 = top of Hyp stack (kernel VA) + * r3 = pointer to hyp vectors + */ + + .text + .pushsection .hyp.idmap.text,"ax" + .align 5 +__kvm_hyp_init: + .globl __kvm_hyp_init + + @ Hyp-mode exception vector + W(b) . + W(b) . + W(b) . + W(b) . + W(b) . + W(b) __do_hyp_init + W(b) . + W(b) . + +__do_hyp_init: + @ Set the HTTBR to point to the hypervisor PGD pointer passed + mcrr p15, 4, r0, r1, c2 + + @ Set the HTCR and VTCR to the same shareability and cacheability + @ settings as the non-secure TTBCR and with T0SZ == 0. + mrc p15, 4, r0, c2, c0, 2 @ HTCR + ldr r12, =HTCR_MASK + bic r0, r0, r12 + mrc p15, 0, r1, c2, c0, 2 @ TTBCR + and r1, r1, #(HTCR_MASK & ~TTBCR_T0SZ) + orr r0, r0, r1 + mcr p15, 4, r0, c2, c0, 2 @ HTCR + + mrc p15, 4, r1, c2, c1, 2 @ VTCR + ldr r12, =VTCR_MASK + bic r1, r1, r12 + bic r0, r0, #(~VTCR_HTCR_SH) @ clear non-reusable HTCR bits + orr r1, r0, r1 + orr r1, r1, #(KVM_VTCR_SL0 | KVM_VTCR_T0SZ | KVM_VTCR_S) + mcr p15, 4, r1, c2, c1, 2 @ VTCR + + @ Use the same memory attributes for hyp. accesses as the kernel + @ (copy MAIRx ro HMAIRx). + mrc p15, 0, r0, c10, c2, 0 + mcr p15, 4, r0, c10, c2, 0 + mrc p15, 0, r0, c10, c2, 1 + mcr p15, 4, r0, c10, c2, 1 + + @ Set the HSCTLR to: + @ - ARM/THUMB exceptions: Kernel config (Thumb-2 kernel) + @ - Endianness: Kernel config + @ - Fast Interrupt Features: Kernel config + @ - Write permission implies XN: disabled + @ - Instruction cache: enabled + @ - Data/Unified cache: enabled + @ - Memory alignment checks: enabled + @ - MMU: enabled (this code must be run from an identity mapping) + mrc p15, 4, r0, c1, c0, 0 @ HSCR + ldr r12, =HSCTLR_MASK + bic r0, r0, r12 + mrc p15, 0, r1, c1, c0, 0 @ SCTLR + ldr r12, =(HSCTLR_EE | HSCTLR_FI | HSCTLR_I | HSCTLR_C) + and r1, r1, r12 + ARM( ldr r12, =(HSCTLR_M | HSCTLR_A) ) + THUMB( ldr r12, =(HSCTLR_M | HSCTLR_A | HSCTLR_TE) ) + orr r1, r1, r12 + orr r0, r0, r1 + isb + mcr p15, 4, r0, c1, c0, 0 @ HSCR + isb + + @ Set stack pointer and return to the kernel + mov sp, r2 + + @ Set HVBAR to point to the HYP vectors + mcr p15, 4, r3, c12, c0, 0 @ HVBAR + + eret + + .ltorg + + .globl __kvm_hyp_init_end +__kvm_hyp_init_end: + + .popsection diff --git a/arch/arm/kvm/interrupts.S b/arch/arm/kvm/interrupts.S index 1dc8926e26d..d10a8075409 100644 --- a/arch/arm/kvm/interrupts.S +++ b/arch/arm/kvm/interrupts.S @@ -15,5 +15,67 @@ * along with this program; if not, write to the Free Software * Foundation, 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA. */ + +#include <linux/linkage.h> +#include <linux/const.h> +#include <asm/unified.h> +#include <asm/page.h> #include <asm/asm-offsets.h> #include <asm/kvm_asm.h> +#include <asm/kvm_arm.h> + + .text + +__kvm_hyp_code_start: + .globl __kvm_hyp_code_start + +/******************************************************************** + * Flush per-VMID TLBs + */ +ENTRY(__kvm_flush_vm_context) + bx lr +ENDPROC(__kvm_flush_vm_context) + +/******************************************************************** + * Hypervisor world-switch code + */ +ENTRY(__kvm_vcpu_run) + bx lr + +/******************************************************************** + * Call function in Hyp mode + * + * + * u64 kvm_call_hyp(void *hypfn, ...); + * + * This is not really a variadic function in the classic C-way and care must + * be taken when calling this to ensure parameters are passed in registers + * only, since the stack will change between the caller and the callee. + * + * Call the function with the first argument containing a pointer to the + * function you wish to call in Hyp mode, and subsequent arguments will be + * passed as r0, r1, and r2 (a maximum of 3 arguments in addition to the + * function pointer can be passed). The function being called must be mapped + * in Hyp mode (see init_hyp_mode in arch/arm/kvm/arm.c). Return values are + * passed in r0 and r1. + * + * The calling convention follows the standard AAPCS: + * r0 - r3: caller save + * r12: caller save + * rest: callee save + */ +ENTRY(kvm_call_hyp) + hvc #0 + bx lr + +/******************************************************************** + * Hypervisor exception vector and handlers + */ + + .align 5 +__kvm_hyp_vector: + .globl __kvm_hyp_vector + nop + +__kvm_hyp_code_end: + .globl __kvm_hyp_code_end diff --git a/arch/arm/kvm/mmu.c b/arch/arm/kvm/mmu.c index 10ed4643269..4decdb61801 100644 --- a/arch/arm/kvm/mmu.c +++ b/arch/arm/kvm/mmu.c @@ -15,3 +15,251 @@ * along with this program; if not, write to the Free Software * Foundation, 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA. */ + +#include <linux/mman.h> +#include <linux/kvm_host.h> +#include <linux/io.h> +#include <asm/idmap.h> +#include <asm/pgalloc.h> +#include <asm/kvm_arm.h> +#include <asm/kvm_mmu.h> +#include <asm/mach/map.h> + +extern char __hyp_idmap_text_start[], __hyp_idmap_text_end[]; + +static DEFINE_MUTEX(kvm_hyp_pgd_mutex); + +static void kvm_set_pte(pte_t *pte, pte_t new_pte) +{ + pte_val(*pte) = new_pte; + /* + * flush_pmd_entry just takes a void pointer and cleans the necessary + * cache entries, so we can reuse the function for ptes. + */ + flush_pmd_entry(pte); +} + +static void free_ptes(pmd_t *pmd, unsigned long addr) +{ + pte_t *pte; + unsigned int i; + + for (i = 0; i < PTRS_PER_PMD; i++, addr += PMD_SIZE) { + if (!pmd_none(*pmd) && pmd_table(*pmd)) { + pte = pte_offset_kernel(pmd, addr); + pte_free_kernel(NULL, pte); + } + pmd++; + } +} + +/** + * free_hyp_pmds - free a Hyp-mode level-2 tables and child level-3 tables + * + * Assumes this is a page table used strictly in Hyp-mode and therefore contains + * only mappings in the kernel memory area, which is above PAGE_OFFSET. + */ +void free_hyp_pmds(void) +{ + pgd_t *pgd; + pud_t *pud; + pmd_t *pmd; + unsigned long addr; + + mutex_lock(&kvm_hyp_pgd_mutex); + for (addr = PAGE_OFFSET; addr != 0; addr += PGDIR_SIZE) { + pgd = hyp_pgd + pgd_index(addr); + pud = pud_offset(pgd, addr); + + if (pud_none(*pud)) + continue; + BUG_ON(pud_bad(*pud)); + + pmd = pmd_offset(pud, addr); + free_ptes(pmd, addr); + pmd_free(NULL, pmd); + pud_clear(pud); + } + mutex_unlock(&kvm_hyp_pgd_mutex); +} + +static void create_hyp_pte_mappings(pmd_t *pmd, unsigned long start, + unsigned long end) +{ + pte_t *pte; + unsigned long addr; + struct page *page; + + for (addr = start & PAGE_MASK; addr < end; addr += PAGE_SIZE) { + pte = pte_offset_kernel(pmd, addr); + BUG_ON(!virt_addr_valid(addr)); + page = virt_to_page(addr); + kvm_set_pte(pte, mk_pte(page, PAGE_HYP)); + } +} + +static void create_hyp_io_pte_mappings(pmd_t *pmd, unsigned long start, + unsigned long end, + unsigned long *pfn_base) +{ + pte_t *pte; + unsigned long addr; + + for (addr = start & PAGE_MASK; addr < end; addr += PAGE_SIZE) { + pte = pte_offset_kernel(pmd, addr); + BUG_ON(pfn_valid(*pfn_base)); + kvm_set_pte(pte, pfn_pte(*pfn_base, PAGE_HYP_DEVICE)); + (*pfn_base)++; + } +} + +static int create_hyp_pmd_mappings(pud_t *pud, unsigned long start, + unsigned long end, unsigned long *pfn_base) +{ + pmd_t *pmd; + pte_t *pte; + unsigned long addr, next; + + for (addr = start; addr < end; addr = next) { + pmd = pmd_offset(pud, addr); + + BUG_ON(pmd_sect(*pmd)); + + if (pmd_none(*pmd)) { + pte = pte_alloc_one_kernel(NULL, addr); + if (!pte) { + kvm_err("Cannot allocate Hyp pte\n"); + return -ENOMEM; + } + pmd_populate_kernel(NULL, pmd, pte); + } + + next = pmd_addr_end(addr, end); + + /* + * If pfn_base is NULL, we map kernel pages into HYP with the + * virtual address. Otherwise, this is considered an I/O + * mapping and we map the physical region starting at + * *pfn_base to [start, end[. + */ + if (!pfn_base) + create_hyp_pte_mappings(pmd, addr, next); + else + create_hyp_io_pte_mappings(pmd, addr, next, pfn_base); + } + + return 0; +} + +static int __create_hyp_mappings(void *from, void *to, unsigned long *pfn_base) +{ + unsigned long start = (unsigned long)from; + unsigned long end = (unsigned long)to; + pgd_t *pgd; + pud_t *pud; + pmd_t *pmd; + unsigned long addr, next; + int err = 0; + + BUG_ON(start > end); + if (start < PAGE_OFFSET) + return -EINVAL; + + mutex_lock(&kvm_hyp_pgd_mutex); + for (addr = start; addr < end; addr = next) { + pgd = hyp_pgd + pgd_index(addr); + pud = pud_offset(pgd, addr); + + if (pud_none_or_clear_bad(pud)) { + pmd = pmd_alloc_one(NULL, addr); + if (!pmd) { + kvm_err("Cannot allocate Hyp pmd\n"); + err = -ENOMEM; + goto out; + } + pud_populate(NULL, pud, pmd); + } + + next = pgd_addr_end(addr, end); + err = create_hyp_pmd_mappings(pud, addr, next, pfn_base); + if (err) + goto out; + } +out: + mutex_unlock(&kvm_hyp_pgd_mutex); + return err; +} + +/** + * create_hyp_mappings - map a kernel virtual address range in Hyp mode + * @from: The virtual kernel start address of the range + * @to: The virtual kernel end address of the range (exclusive) + * + * The same virtual address as the kernel virtual address is also used in + * Hyp-mode mapping to the same underlying physical pages. + * + * Note: Wrapping around zero in the "to" address is not supported. + */ +int create_hyp_mappings(void *from, void *to) +{ + return __create_hyp_mappings(from, to, NULL); +} + +/** + * create_hyp_io_mappings - map a physical IO range in Hyp mode + * @from: The virtual HYP start address of the range + * @to: The virtual HYP end address of the range (exclusive) + * @addr: The physical start address which gets mapped + */ +int create_hyp_io_mappings(void *from, void *to, phys_addr_t addr) +{ + unsigned long pfn = __phys_to_pfn(addr); + return __create_hyp_mappings(from, to, &pfn); +} + +int kvm_handle_guest_abort(struct kvm_vcpu *vcpu, struct kvm_run *run) +{ + return -EINVAL; +} + +phys_addr_t kvm_mmu_get_httbr(void) +{ + VM_BUG_ON(!virt_addr_valid(hyp_pgd)); + return virt_to_phys(hyp_pgd); +} + +int kvm_mmu_init(void) +{ + return hyp_pgd ? 0 : -ENOMEM; +} + +/** + * kvm_clear_idmap - remove all idmaps from the hyp pgd + * + * Free the underlying pmds for all pgds in range and clear the pgds (but + * don't free them) afterwards. + */ +void kvm_clear_hyp_idmap(void) +{ + unsigned long addr, end; + unsigned long next; + pgd_t *pgd = hyp_pgd; + pud_t *pud; + pmd_t *pmd; + + addr = virt_to_phys(__hyp_idmap_text_start); + end = virt_to_phys(__hyp_idmap_text_end); + + pgd += pgd_index(addr); + do { + next = pgd_addr_end(addr, end); + if (pgd_none_or_clear_bad(pgd)) + continue; + pud = pud_offset(pgd, addr); + pmd = pmd_offset(pud, addr); + + pud_clear(pud); + clean_pmd_entry(pmd); + pmd_free(NULL, (pmd_t *)((unsigned long)pmd & PAGE_MASK)); + } while (pgd++, addr = next, addr < end); +} |