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Add a nr_pages argument to the __pkvm_host_share_guest hypercall. This range supports only two values: 1 or PMD_SIZE / PAGE_SIZE (that is 512 on a 4K-pages system). Signed-off-by: Vincent Donnefort diff --git a/arch/arm64/kvm/hyp/include/nvhe/mem_protect.h b/arch/arm64/kvm= /hyp/include/nvhe/mem_protect.h index 978f38c386ee..1abbab5e2ff8 100644 --- a/arch/arm64/kvm/hyp/include/nvhe/mem_protect.h +++ b/arch/arm64/kvm/hyp/include/nvhe/mem_protect.h @@ -39,7 +39,7 @@ int __pkvm_host_donate_hyp(u64 pfn, u64 nr_pages); int __pkvm_hyp_donate_host(u64 pfn, u64 nr_pages); int __pkvm_host_share_ffa(u64 pfn, u64 nr_pages); int __pkvm_host_unshare_ffa(u64 pfn, u64 nr_pages); -int __pkvm_host_share_guest(u64 pfn, u64 gfn, struct pkvm_hyp_vcpu *vcpu, +int __pkvm_host_share_guest(u64 pfn, u64 gfn, u64 nr_pages, struct pkvm_hy= p_vcpu *vcpu, enum kvm_pgtable_prot prot); int __pkvm_host_unshare_guest(u64 gfn, struct pkvm_hyp_vm *hyp_vm); int __pkvm_host_relax_perms_guest(u64 gfn, struct pkvm_hyp_vcpu *vcpu, enu= m kvm_pgtable_prot prot); diff --git a/arch/arm64/kvm/hyp/nvhe/hyp-main.c b/arch/arm64/kvm/hyp/nvhe/h= yp-main.c index 2c37680d954c..e71601746935 100644 --- a/arch/arm64/kvm/hyp/nvhe/hyp-main.c +++ b/arch/arm64/kvm/hyp/nvhe/hyp-main.c @@ -249,7 +249,8 @@ static void handle___pkvm_host_share_guest(struct kvm_c= pu_context *host_ctxt) { DECLARE_REG(u64, pfn, host_ctxt, 1); DECLARE_REG(u64, gfn, host_ctxt, 2); - DECLARE_REG(enum kvm_pgtable_prot, prot, host_ctxt, 3); + DECLARE_REG(u64, nr_pages, host_ctxt, 3); + DECLARE_REG(enum kvm_pgtable_prot, prot, host_ctxt, 4); struct pkvm_hyp_vcpu *hyp_vcpu; int ret =3D -EINVAL; =20 @@ -264,7 +265,7 @@ static void handle___pkvm_host_share_guest(struct kvm_c= pu_context *host_ctxt) if (ret) goto out; =20 - ret =3D __pkvm_host_share_guest(pfn, gfn, hyp_vcpu, prot); + ret =3D __pkvm_host_share_guest(pfn, gfn, nr_pages, hyp_vcpu, prot); out: cpu_reg(host_ctxt, 1) =3D ret; } diff --git a/arch/arm64/kvm/hyp/nvhe/mem_protect.c b/arch/arm64/kvm/hyp/nvh= e/mem_protect.c index 63968c7740c3..7e3a249149a0 100644 --- a/arch/arm64/kvm/hyp/nvhe/mem_protect.c +++ b/arch/arm64/kvm/hyp/nvhe/mem_protect.c @@ -60,6 +60,9 @@ static void hyp_unlock_component(void) hyp_spin_unlock(&pkvm_pgd_lock); } =20 +#define for_each_hyp_page(start, size, page) \ + for (page =3D hyp_phys_to_page(start); page < hyp_phys_to_page((start) + = (size)); page++) + static void *host_s2_zalloc_pages_exact(size_t size) { void *addr =3D hyp_alloc_pages(&host_s2_pool, get_order(size)); @@ -509,10 +512,25 @@ int host_stage2_idmap_locked(phys_addr_t addr, u64 si= ze, =20 static void __host_update_page_state(phys_addr_t addr, u64 size, enum pkvm= _page_state state) { - phys_addr_t end =3D addr + size; + struct hyp_page *page; =20 - for (; addr < end; addr +=3D PAGE_SIZE) - hyp_phys_to_page(addr)->host_state =3D state; + for_each_hyp_page(addr, size, page) + page->host_state =3D state; +} + +static void __host_update_share_guest_count(u64 phys, u64 size, bool inc) +{ + struct hyp_page *page; + + for_each_hyp_page(phys, size, page) { + if (inc) { + WARN_ON(page->host_share_guest_count++ =3D=3D U32_MAX); + } else { + WARN_ON(!page->host_share_guest_count--); + if (!page->host_share_guest_count) + page->host_state =3D PKVM_PAGE_OWNED; + } + } } =20 int host_stage2_set_owner_locked(phys_addr_t addr, u64 size, u8 owner_id) @@ -627,16 +645,16 @@ static int check_page_state_range(struct kvm_pgtable = *pgt, u64 addr, u64 size, static int __host_check_page_state_range(u64 addr, u64 size, enum pkvm_page_state state) { - u64 end =3D addr + size; + struct hyp_page *page; int ret; =20 - ret =3D check_range_allowed_memory(addr, end); + ret =3D check_range_allowed_memory(addr, addr + size); if (ret) return ret; =20 hyp_assert_lock_held(&host_mmu.lock); - for (; addr < end; addr +=3D PAGE_SIZE) { - if (hyp_phys_to_page(addr)->host_state !=3D state) + for_each_hyp_page(addr, size, page) { + if (page->host_state !=3D state) return -EPERM; } =20 @@ -686,10 +704,9 @@ static enum pkvm_page_state guest_get_page_state(kvm_p= te_t pte, u64 addr) return pkvm_getstate(kvm_pgtable_stage2_pte_prot(pte)); } =20 -static int __guest_check_page_state_range(struct pkvm_hyp_vcpu *vcpu, u64 = addr, +static int __guest_check_page_state_range(struct pkvm_hyp_vm *vm, u64 addr, u64 size, enum pkvm_page_state state) { - struct pkvm_hyp_vm *vm =3D pkvm_hyp_vcpu_to_hyp_vm(vcpu); struct check_walk_data d =3D { .desired =3D state, .get_page_state =3D guest_get_page_state, @@ -896,49 +913,83 @@ int __pkvm_host_unshare_ffa(u64 pfn, u64 nr_pages) return ret; } =20 -int __pkvm_host_share_guest(u64 pfn, u64 gfn, struct pkvm_hyp_vcpu *vcpu, +static int __guest_check_transition_size(u64 phys, u64 ipa, u64 nr_pages, = u64 *size) +{ + if (nr_pages =3D=3D 1) { + *size =3D PAGE_SIZE; + return 0; + } + + /* We solely support PMD_SIZE huge-pages */ + if (nr_pages !=3D (1 << (PMD_SHIFT - PAGE_SHIFT))) + return -EINVAL; + + if (!IS_ALIGNED(phys | ipa, PMD_SIZE)) + return -EINVAL; + + *size =3D PMD_SIZE; + return 0; +} + +int __pkvm_host_share_guest(u64 pfn, u64 gfn, u64 nr_pages, struct pkvm_hy= p_vcpu *vcpu, enum kvm_pgtable_prot prot) { struct pkvm_hyp_vm *vm =3D pkvm_hyp_vcpu_to_hyp_vm(vcpu); u64 phys =3D hyp_pfn_to_phys(pfn); u64 ipa =3D hyp_pfn_to_phys(gfn); + enum pkvm_page_state state; struct hyp_page *page; + u64 size; int ret; =20 if (prot & ~KVM_PGTABLE_PROT_RWX) return -EINVAL; =20 - ret =3D check_range_allowed_memory(phys, phys + PAGE_SIZE); + ret =3D __guest_check_transition_size(phys, ipa, nr_pages, &size); + if (ret) + return ret; + + ret =3D check_range_allowed_memory(phys, phys + size); if (ret) return ret; =20 host_lock_component(); guest_lock_component(vm); =20 - ret =3D __guest_check_page_state_range(vcpu, ipa, PAGE_SIZE, PKVM_NOPAGE); + ret =3D __guest_check_page_state_range(vm, ipa, size, PKVM_NOPAGE); if (ret) goto unlock; =20 - page =3D hyp_phys_to_page(phys); - switch (page->host_state) { + state =3D hyp_phys_to_page(phys)->host_state; + for_each_hyp_page(phys, size, page) { + if (page->host_state !=3D state) { + ret =3D -EPERM; + goto unlock; + } + } + + switch (state) { case PKVM_PAGE_OWNED: - WARN_ON(__host_set_page_state_range(phys, PAGE_SIZE, PKVM_PAGE_SHARED_OW= NED)); + WARN_ON(__host_set_page_state_range(phys, size, PKVM_PAGE_SHARED_OWNED)); break; case PKVM_PAGE_SHARED_OWNED: - if (page->host_share_guest_count) - break; - /* Only host to np-guest multi-sharing is tolerated */ - WARN_ON(1); - fallthrough; + for_each_hyp_page(phys, size, page) { + /* Only host to np-guest multi-sharing is tolerated */ + if (WARN_ON(!page->host_share_guest_count)) { + ret =3D -EPERM; + goto unlock; + } + } + break; default: ret =3D -EPERM; goto unlock; } =20 - WARN_ON(kvm_pgtable_stage2_map(&vm->pgt, ipa, PAGE_SIZE, phys, + WARN_ON(kvm_pgtable_stage2_map(&vm->pgt, ipa, size, phys, pkvm_mkstate(prot, PKVM_PAGE_SHARED_BORROWED), &vcpu->vcpu.arch.pkvm_memcache, 0)); - page->host_share_guest_count++; + __host_update_share_guest_count(phys, size, true); =20 unlock: guest_unlock_component(vm); diff --git a/arch/arm64/kvm/pkvm.c b/arch/arm64/kvm/pkvm.c index 930b677eb9b0..00fd9a524bf7 100644 --- a/arch/arm64/kvm/pkvm.c +++ b/arch/arm64/kvm/pkvm.c @@ -361,7 +361,7 @@ int pkvm_pgtable_stage2_map(struct kvm_pgtable *pgt, u6= 4 addr, u64 size, return -EINVAL; =20 lockdep_assert_held_write(&kvm->mmu_lock); - ret =3D kvm_call_hyp_nvhe(__pkvm_host_share_guest, pfn, gfn, prot); + ret =3D kvm_call_hyp_nvhe(__pkvm_host_share_guest, pfn, gfn, 1, prot); if (ret) { /* Is the gfn already mapped due to a racing vCPU? */ if (ret =3D=3D -EPERM) --=20 2.48.1.711.g2feabab25a-goog