From: Quentin Perret <qper...@google.com> Extend the shadow initialisation at EL2 so that we instantiate a memory pool and a full 'struct kvm_s2_mmu' structure for each VM, with a stage-2 page-table entirely independent from the one managed by the host at EL1.
For now, the new page-table is unused as there is no way for the host to map anything into it. Yet. Signed-off-by: Quentin Perret <qper...@google.com> Signed-off-by: Will Deacon <w...@kernel.org> --- arch/arm64/kvm/hyp/include/nvhe/pkvm.h | 6 ++ arch/arm64/kvm/hyp/nvhe/mem_protect.c | 127 ++++++++++++++++++++++++- 2 files changed, 130 insertions(+), 3 deletions(-) diff --git a/arch/arm64/kvm/hyp/include/nvhe/pkvm.h b/arch/arm64/kvm/hyp/include/nvhe/pkvm.h index 1d0a33f70879..c0e32a750b6e 100644 --- a/arch/arm64/kvm/hyp/include/nvhe/pkvm.h +++ b/arch/arm64/kvm/hyp/include/nvhe/pkvm.h @@ -9,6 +9,9 @@ #include <asm/kvm_pkvm.h> +#include <nvhe/gfp.h> +#include <nvhe/spinlock.h> + /* * Holds the relevant data for maintaining the vcpu state completely at hyp. */ @@ -37,6 +40,9 @@ struct kvm_shadow_vm { size_t shadow_area_size; struct kvm_pgtable pgt; + struct kvm_pgtable_mm_ops mm_ops; + struct hyp_pool pool; + hyp_spinlock_t lock; /* Array of the shadow state per vcpu. */ struct kvm_shadow_vcpu_state shadow_vcpu_states[0]; diff --git a/arch/arm64/kvm/hyp/nvhe/mem_protect.c b/arch/arm64/kvm/hyp/nvhe/mem_protect.c index a0af23de2640..5b22bba77e57 100644 --- a/arch/arm64/kvm/hyp/nvhe/mem_protect.c +++ b/arch/arm64/kvm/hyp/nvhe/mem_protect.c @@ -25,6 +25,21 @@ struct host_kvm host_kvm; static struct hyp_pool host_s2_pool; +static DEFINE_PER_CPU(struct kvm_shadow_vm *, __current_vm); +#define current_vm (*this_cpu_ptr(&__current_vm)) + +static void guest_lock_component(struct kvm_shadow_vm *vm) +{ + hyp_spin_lock(&vm->lock); + current_vm = vm; +} + +static void guest_unlock_component(struct kvm_shadow_vm *vm) +{ + current_vm = NULL; + hyp_spin_unlock(&vm->lock); +} + static void host_lock_component(void) { hyp_spin_lock(&host_kvm.lock); @@ -140,18 +155,124 @@ int kvm_host_prepare_stage2(void *pgt_pool_base) return 0; } +static bool guest_stage2_force_pte_cb(u64 addr, u64 end, + enum kvm_pgtable_prot prot) +{ + return true; +} + +static void *guest_s2_zalloc_pages_exact(size_t size) +{ + void *addr = hyp_alloc_pages(¤t_vm->pool, get_order(size)); + + WARN_ON(size != (PAGE_SIZE << get_order(size))); + hyp_split_page(hyp_virt_to_page(addr)); + + return addr; +} + +static void guest_s2_free_pages_exact(void *addr, unsigned long size) +{ + u8 order = get_order(size); + unsigned int i; + + for (i = 0; i < (1 << order); i++) + hyp_put_page(¤t_vm->pool, addr + (i * PAGE_SIZE)); +} + +static void *guest_s2_zalloc_page(void *mc) +{ + struct hyp_page *p; + void *addr; + + addr = hyp_alloc_pages(¤t_vm->pool, 0); + if (addr) + return addr; + + addr = pop_hyp_memcache(mc, hyp_phys_to_virt); + if (!addr) + return addr; + + memset(addr, 0, PAGE_SIZE); + p = hyp_virt_to_page(addr); + memset(p, 0, sizeof(*p)); + p->refcount = 1; + + return addr; +} + +static void guest_s2_get_page(void *addr) +{ + hyp_get_page(¤t_vm->pool, addr); +} + +static void guest_s2_put_page(void *addr) +{ + hyp_put_page(¤t_vm->pool, addr); +} + +static void clean_dcache_guest_page(void *va, size_t size) +{ + __clean_dcache_guest_page(hyp_fixmap_map(__hyp_pa(va)), size); + hyp_fixmap_unmap(); +} + +static void invalidate_icache_guest_page(void *va, size_t size) +{ + __invalidate_icache_guest_page(hyp_fixmap_map(__hyp_pa(va)), size); + hyp_fixmap_unmap(); +} + int kvm_guest_prepare_stage2(struct kvm_shadow_vm *vm, void *pgd) { - vm->pgt.pgd = pgd; + struct kvm_s2_mmu *mmu = &vm->kvm.arch.mmu; + unsigned long nr_pages; + int ret; + + nr_pages = kvm_pgtable_stage2_pgd_size(vm->kvm.arch.vtcr) >> PAGE_SHIFT; + ret = hyp_pool_init(&vm->pool, hyp_virt_to_pfn(pgd), nr_pages, 0); + if (ret) + return ret; + + hyp_spin_lock_init(&vm->lock); + vm->mm_ops = (struct kvm_pgtable_mm_ops) { + .zalloc_pages_exact = guest_s2_zalloc_pages_exact, + .free_pages_exact = guest_s2_free_pages_exact, + .zalloc_page = guest_s2_zalloc_page, + .phys_to_virt = hyp_phys_to_virt, + .virt_to_phys = hyp_virt_to_phys, + .page_count = hyp_page_count, + .get_page = guest_s2_get_page, + .put_page = guest_s2_put_page, + .dcache_clean_inval_poc = clean_dcache_guest_page, + .icache_inval_pou = invalidate_icache_guest_page, + }; + + guest_lock_component(vm); + ret = __kvm_pgtable_stage2_init(mmu->pgt, mmu, &vm->mm_ops, 0, + guest_stage2_force_pte_cb); + guest_unlock_component(vm); + if (ret) + return ret; + + vm->kvm.arch.mmu.pgd_phys = __hyp_pa(vm->pgt.pgd); + return 0; } void reclaim_guest_pages(struct kvm_shadow_vm *vm) { - unsigned long nr_pages; + unsigned long nr_pages, pfn; nr_pages = kvm_pgtable_stage2_pgd_size(vm->kvm.arch.vtcr) >> PAGE_SHIFT; - WARN_ON(__pkvm_hyp_donate_host(hyp_virt_to_pfn(vm->pgt.pgd), nr_pages)); + pfn = hyp_virt_to_pfn(vm->pgt.pgd); + + guest_lock_component(vm); + kvm_pgtable_stage2_destroy(&vm->pgt); + vm->kvm.arch.mmu.pgd_phys = 0ULL; + guest_unlock_component(vm); + + WARN_ON(__pkvm_hyp_donate_host(pfn, nr_pages)); } int __pkvm_prot_finalize(void) -- 2.37.0.rc0.161.g10f37bed90-goog _______________________________________________ kvmarm mailing list kvmarm@lists.cs.columbia.edu https://lists.cs.columbia.edu/mailman/listinfo/kvmarm