| Message ID | 20241216175803.2716565-11-qperret@google.com (mailing list archive) |
|---|---|
| State | New |
| Headers | show |
| Series | KVM: arm64: Non-protected guest stage-2 support for pKVM | expand |
On Mon, 16 Dec 2024 at 17:58, Quentin Perret <qperret@google.com> wrote: > > In preparation for handling guest stage-2 mappings at EL2, introduce a > new pKVM hypercall allowing to share pages with non-protected guests. > > Signed-off-by: Quentin Perret <qperret@google.com> (Apart from a nit below) Reviewed-by: Fuad Tabba <tabba@google.com> Cheers, /fuad > --- > arch/arm64/include/asm/kvm_asm.h | 1 + > arch/arm64/include/asm/kvm_host.h | 3 + > arch/arm64/kvm/hyp/include/nvhe/mem_protect.h | 1 + > arch/arm64/kvm/hyp/include/nvhe/memory.h | 2 + > arch/arm64/kvm/hyp/nvhe/hyp-main.c | 34 +++++++++ > arch/arm64/kvm/hyp/nvhe/mem_protect.c | 72 +++++++++++++++++++ > arch/arm64/kvm/hyp/nvhe/pkvm.c | 7 ++ > 7 files changed, 120 insertions(+) > > diff --git a/arch/arm64/include/asm/kvm_asm.h b/arch/arm64/include/asm/kvm_asm.h > index 89c0fac69551..449337f5b2a3 100644 > --- a/arch/arm64/include/asm/kvm_asm.h > +++ b/arch/arm64/include/asm/kvm_asm.h > @@ -65,6 +65,7 @@ enum __kvm_host_smccc_func { > /* Hypercalls available after pKVM finalisation */ > __KVM_HOST_SMCCC_FUNC___pkvm_host_share_hyp, > __KVM_HOST_SMCCC_FUNC___pkvm_host_unshare_hyp, > + __KVM_HOST_SMCCC_FUNC___pkvm_host_share_guest, > __KVM_HOST_SMCCC_FUNC___kvm_adjust_pc, > __KVM_HOST_SMCCC_FUNC___kvm_vcpu_run, > __KVM_HOST_SMCCC_FUNC___kvm_flush_vm_context, > diff --git a/arch/arm64/include/asm/kvm_host.h b/arch/arm64/include/asm/kvm_host.h > index e18e9244d17a..1246f1d01dbf 100644 > --- a/arch/arm64/include/asm/kvm_host.h > +++ b/arch/arm64/include/asm/kvm_host.h > @@ -771,6 +771,9 @@ struct kvm_vcpu_arch { > /* Cache some mmu pages needed inside spinlock regions */ > struct kvm_mmu_memory_cache mmu_page_cache; > > + /* Pages to top-up the pKVM/EL2 guest pool */ > + struct kvm_hyp_memcache pkvm_memcache; > + > /* Virtual SError ESR to restore when HCR_EL2.VSE is set */ > u64 vsesr_el2; > > diff --git a/arch/arm64/kvm/hyp/include/nvhe/mem_protect.h b/arch/arm64/kvm/hyp/include/nvhe/mem_protect.h > index 25038ac705d8..a7976e50f556 100644 > --- a/arch/arm64/kvm/hyp/include/nvhe/mem_protect.h > +++ b/arch/arm64/kvm/hyp/include/nvhe/mem_protect.h > @@ -39,6 +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, enum kvm_pgtable_prot prot); > > bool addr_is_memory(phys_addr_t phys); > int host_stage2_idmap_locked(phys_addr_t addr, u64 size, enum kvm_pgtable_prot prot); > diff --git a/arch/arm64/kvm/hyp/include/nvhe/memory.h b/arch/arm64/kvm/hyp/include/nvhe/memory.h > index 8bd9a539f260..cc431820c6ce 100644 > --- a/arch/arm64/kvm/hyp/include/nvhe/memory.h > +++ b/arch/arm64/kvm/hyp/include/nvhe/memory.h > @@ -46,6 +46,8 @@ struct hyp_page { > > /* Host (non-meta) state. Guarded by the host stage-2 lock. */ > enum pkvm_page_state host_state : 8; > + > + u32 host_share_guest_count; > }; > > extern u64 __hyp_vmemmap; > diff --git a/arch/arm64/kvm/hyp/nvhe/hyp-main.c b/arch/arm64/kvm/hyp/nvhe/hyp-main.c > index 95d78db315b3..d659462fbf5d 100644 > --- a/arch/arm64/kvm/hyp/nvhe/hyp-main.c > +++ b/arch/arm64/kvm/hyp/nvhe/hyp-main.c > @@ -211,6 +211,39 @@ static void handle___kvm_vcpu_run(struct kvm_cpu_context *host_ctxt) > cpu_reg(host_ctxt, 1) = ret; > } > > +static int pkvm_refill_memcache(struct pkvm_hyp_vcpu *hyp_vcpu) > +{ > + struct kvm_vcpu *host_vcpu = hyp_vcpu->host_vcpu; > + > + return refill_memcache(&hyp_vcpu->vcpu.arch.pkvm_memcache, > + host_vcpu->arch.pkvm_memcache.nr_pages, > + &host_vcpu->arch.pkvm_memcache); > +} > + > +static void handle___pkvm_host_share_guest(struct kvm_cpu_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); > + struct pkvm_hyp_vcpu *hyp_vcpu; > + int ret = -EINVAL; > + > + if (!is_protected_kvm_enabled()) > + goto out; > + > + hyp_vcpu = pkvm_get_loaded_hyp_vcpu(); > + if (!hyp_vcpu || pkvm_hyp_vcpu_is_protected(hyp_vcpu)) > + goto out; > + > + ret = pkvm_refill_memcache(hyp_vcpu); > + if (ret) > + goto out; > + > + ret = __pkvm_host_share_guest(pfn, gfn, hyp_vcpu, prot); > +out: > + cpu_reg(host_ctxt, 1) = ret; > +} > + > static void handle___kvm_adjust_pc(struct kvm_cpu_context *host_ctxt) > { > DECLARE_REG(struct kvm_vcpu *, vcpu, host_ctxt, 1); > @@ -420,6 +453,7 @@ static const hcall_t host_hcall[] = { > > HANDLE_FUNC(__pkvm_host_share_hyp), > HANDLE_FUNC(__pkvm_host_unshare_hyp), > + HANDLE_FUNC(__pkvm_host_share_guest), > HANDLE_FUNC(__kvm_adjust_pc), > HANDLE_FUNC(__kvm_vcpu_run), > HANDLE_FUNC(__kvm_flush_vm_context), > diff --git a/arch/arm64/kvm/hyp/nvhe/mem_protect.c b/arch/arm64/kvm/hyp/nvhe/mem_protect.c > index 12bb5445fe47..fb9592e721cf 100644 > --- a/arch/arm64/kvm/hyp/nvhe/mem_protect.c > +++ b/arch/arm64/kvm/hyp/nvhe/mem_protect.c > @@ -867,6 +867,27 @@ static int hyp_complete_donation(u64 addr, > return pkvm_create_mappings_locked(start, end, prot); > } > > +static enum pkvm_page_state guest_get_page_state(kvm_pte_t pte, u64 addr) > +{ > + if (!kvm_pte_valid(pte)) > + return PKVM_NOPAGE; > + > + return pkvm_getstate(kvm_pgtable_stage2_pte_prot(pte)); > +} > + > +static int __guest_check_page_state_range(struct pkvm_hyp_vcpu *vcpu, u64 addr, > + u64 size, enum pkvm_page_state state) > +{ > + struct pkvm_hyp_vm *vm = pkvm_hyp_vcpu_to_hyp_vm(vcpu); > + struct check_walk_data d = { > + .desired = state, > + .get_page_state = guest_get_page_state, > + }; > + > + hyp_assert_lock_held(&vm->lock); > + return check_page_state_range(&vm->pgt, addr, size, &d); > +} > + > static int check_share(struct pkvm_mem_share *share) > { > const struct pkvm_mem_transition *tx = &share->tx; > @@ -1349,3 +1370,54 @@ int __pkvm_host_unshare_ffa(u64 pfn, u64 nr_pages) > > return ret; > } > + > +int __pkvm_host_share_guest(u64 pfn, u64 gfn, struct pkvm_hyp_vcpu *vcpu, > + enum kvm_pgtable_prot prot) > +{ > + struct pkvm_hyp_vm *vm = pkvm_hyp_vcpu_to_hyp_vm(vcpu); > + u64 phys = hyp_pfn_to_phys(pfn); > + u64 ipa = hyp_pfn_to_phys(gfn); > + struct hyp_page *page; > + int ret; > + > + if (prot & ~KVM_PGTABLE_PROT_RWX) > + return -EINVAL; > + > + ret = check_range_allowed_memory(phys, phys + PAGE_SIZE); > + if (ret) > + return ret; > + > + host_lock_component(); > + guest_lock_component(vm); > + > + ret = __guest_check_page_state_range(vcpu, ipa, PAGE_SIZE, PKVM_NOPAGE); > + if (ret) > + goto unlock; > + > + page = hyp_phys_to_page(phys); > + switch (page->host_state) { > + case PKVM_PAGE_OWNED: > + WARN_ON(__host_set_page_state_range(phys, PAGE_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; > + default: > + ret = -EPERM; > + goto unlock; > + } > + > + WARN_ON(kvm_pgtable_stage2_map(&vm->pgt, ipa, PAGE_SIZE, phys, > + pkvm_mkstate(prot, PKVM_PAGE_SHARED_BORROWED), > + &vcpu->vcpu.arch.pkvm_memcache, 0)); > + page->host_share_guest_count++; > + > +unlock: > + guest_unlock_component(vm); > + host_unlock_component(); > + > + return ret; > +} > diff --git a/arch/arm64/kvm/hyp/nvhe/pkvm.c b/arch/arm64/kvm/hyp/nvhe/pkvm.c > index 496d186efb03..f2e363fe6b84 100644 > --- a/arch/arm64/kvm/hyp/nvhe/pkvm.c > +++ b/arch/arm64/kvm/hyp/nvhe/pkvm.c > @@ -795,6 +795,13 @@ int __pkvm_teardown_vm(pkvm_handle_t handle) > /* Push the metadata pages to the teardown memcache */ > for (idx = 0; idx < hyp_vm->nr_vcpus; ++idx) { > struct pkvm_hyp_vcpu *hyp_vcpu = hyp_vm->vcpus[idx]; > + struct kvm_hyp_memcache *vcpu_mc = &hyp_vcpu->vcpu.arch.pkvm_memcache; > + > + while (vcpu_mc->nr_pages) { > + void *addr = pop_hyp_memcache(vcpu_mc, hyp_phys_to_virt); nit: newline > + push_hyp_memcache(mc, addr, hyp_virt_to_phys); > + unmap_donated_memory_noclear(addr, PAGE_SIZE); > + } > > teardown_donated_memory(mc, hyp_vcpu, sizeof(*hyp_vcpu)); > } > -- > 2.47.1.613.gc27f4b7a9f-goog >
diff --git a/arch/arm64/include/asm/kvm_asm.h b/arch/arm64/include/asm/kvm_asm.h index 89c0fac69551..449337f5b2a3 100644 --- a/arch/arm64/include/asm/kvm_asm.h +++ b/arch/arm64/include/asm/kvm_asm.h @@ -65,6 +65,7 @@ enum __kvm_host_smccc_func { /* Hypercalls available after pKVM finalisation */ __KVM_HOST_SMCCC_FUNC___pkvm_host_share_hyp, __KVM_HOST_SMCCC_FUNC___pkvm_host_unshare_hyp, + __KVM_HOST_SMCCC_FUNC___pkvm_host_share_guest, __KVM_HOST_SMCCC_FUNC___kvm_adjust_pc, __KVM_HOST_SMCCC_FUNC___kvm_vcpu_run, __KVM_HOST_SMCCC_FUNC___kvm_flush_vm_context, diff --git a/arch/arm64/include/asm/kvm_host.h b/arch/arm64/include/asm/kvm_host.h index e18e9244d17a..1246f1d01dbf 100644 --- a/arch/arm64/include/asm/kvm_host.h +++ b/arch/arm64/include/asm/kvm_host.h @@ -771,6 +771,9 @@ struct kvm_vcpu_arch { /* Cache some mmu pages needed inside spinlock regions */ struct kvm_mmu_memory_cache mmu_page_cache; + /* Pages to top-up the pKVM/EL2 guest pool */ + struct kvm_hyp_memcache pkvm_memcache; + /* Virtual SError ESR to restore when HCR_EL2.VSE is set */ u64 vsesr_el2; diff --git a/arch/arm64/kvm/hyp/include/nvhe/mem_protect.h b/arch/arm64/kvm/hyp/include/nvhe/mem_protect.h index 25038ac705d8..a7976e50f556 100644 --- a/arch/arm64/kvm/hyp/include/nvhe/mem_protect.h +++ b/arch/arm64/kvm/hyp/include/nvhe/mem_protect.h @@ -39,6 +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, enum kvm_pgtable_prot prot); bool addr_is_memory(phys_addr_t phys); int host_stage2_idmap_locked(phys_addr_t addr, u64 size, enum kvm_pgtable_prot prot); diff --git a/arch/arm64/kvm/hyp/include/nvhe/memory.h b/arch/arm64/kvm/hyp/include/nvhe/memory.h index 8bd9a539f260..cc431820c6ce 100644 --- a/arch/arm64/kvm/hyp/include/nvhe/memory.h +++ b/arch/arm64/kvm/hyp/include/nvhe/memory.h @@ -46,6 +46,8 @@ struct hyp_page { /* Host (non-meta) state. Guarded by the host stage-2 lock. */ enum pkvm_page_state host_state : 8; + + u32 host_share_guest_count; }; extern u64 __hyp_vmemmap; diff --git a/arch/arm64/kvm/hyp/nvhe/hyp-main.c b/arch/arm64/kvm/hyp/nvhe/hyp-main.c index 95d78db315b3..d659462fbf5d 100644 --- a/arch/arm64/kvm/hyp/nvhe/hyp-main.c +++ b/arch/arm64/kvm/hyp/nvhe/hyp-main.c @@ -211,6 +211,39 @@ static void handle___kvm_vcpu_run(struct kvm_cpu_context *host_ctxt) cpu_reg(host_ctxt, 1) = ret; } +static int pkvm_refill_memcache(struct pkvm_hyp_vcpu *hyp_vcpu) +{ + struct kvm_vcpu *host_vcpu = hyp_vcpu->host_vcpu; + + return refill_memcache(&hyp_vcpu->vcpu.arch.pkvm_memcache, + host_vcpu->arch.pkvm_memcache.nr_pages, + &host_vcpu->arch.pkvm_memcache); +} + +static void handle___pkvm_host_share_guest(struct kvm_cpu_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); + struct pkvm_hyp_vcpu *hyp_vcpu; + int ret = -EINVAL; + + if (!is_protected_kvm_enabled()) + goto out; + + hyp_vcpu = pkvm_get_loaded_hyp_vcpu(); + if (!hyp_vcpu || pkvm_hyp_vcpu_is_protected(hyp_vcpu)) + goto out; + + ret = pkvm_refill_memcache(hyp_vcpu); + if (ret) + goto out; + + ret = __pkvm_host_share_guest(pfn, gfn, hyp_vcpu, prot); +out: + cpu_reg(host_ctxt, 1) = ret; +} + static void handle___kvm_adjust_pc(struct kvm_cpu_context *host_ctxt) { DECLARE_REG(struct kvm_vcpu *, vcpu, host_ctxt, 1); @@ -420,6 +453,7 @@ static const hcall_t host_hcall[] = { HANDLE_FUNC(__pkvm_host_share_hyp), HANDLE_FUNC(__pkvm_host_unshare_hyp), + HANDLE_FUNC(__pkvm_host_share_guest), HANDLE_FUNC(__kvm_adjust_pc), HANDLE_FUNC(__kvm_vcpu_run), HANDLE_FUNC(__kvm_flush_vm_context), diff --git a/arch/arm64/kvm/hyp/nvhe/mem_protect.c b/arch/arm64/kvm/hyp/nvhe/mem_protect.c index 12bb5445fe47..fb9592e721cf 100644 --- a/arch/arm64/kvm/hyp/nvhe/mem_protect.c +++ b/arch/arm64/kvm/hyp/nvhe/mem_protect.c @@ -867,6 +867,27 @@ static int hyp_complete_donation(u64 addr, return pkvm_create_mappings_locked(start, end, prot); } +static enum pkvm_page_state guest_get_page_state(kvm_pte_t pte, u64 addr) +{ + if (!kvm_pte_valid(pte)) + return PKVM_NOPAGE; + + return pkvm_getstate(kvm_pgtable_stage2_pte_prot(pte)); +} + +static int __guest_check_page_state_range(struct pkvm_hyp_vcpu *vcpu, u64 addr, + u64 size, enum pkvm_page_state state) +{ + struct pkvm_hyp_vm *vm = pkvm_hyp_vcpu_to_hyp_vm(vcpu); + struct check_walk_data d = { + .desired = state, + .get_page_state = guest_get_page_state, + }; + + hyp_assert_lock_held(&vm->lock); + return check_page_state_range(&vm->pgt, addr, size, &d); +} + static int check_share(struct pkvm_mem_share *share) { const struct pkvm_mem_transition *tx = &share->tx; @@ -1349,3 +1370,54 @@ int __pkvm_host_unshare_ffa(u64 pfn, u64 nr_pages) return ret; } + +int __pkvm_host_share_guest(u64 pfn, u64 gfn, struct pkvm_hyp_vcpu *vcpu, + enum kvm_pgtable_prot prot) +{ + struct pkvm_hyp_vm *vm = pkvm_hyp_vcpu_to_hyp_vm(vcpu); + u64 phys = hyp_pfn_to_phys(pfn); + u64 ipa = hyp_pfn_to_phys(gfn); + struct hyp_page *page; + int ret; + + if (prot & ~KVM_PGTABLE_PROT_RWX) + return -EINVAL; + + ret = check_range_allowed_memory(phys, phys + PAGE_SIZE); + if (ret) + return ret; + + host_lock_component(); + guest_lock_component(vm); + + ret = __guest_check_page_state_range(vcpu, ipa, PAGE_SIZE, PKVM_NOPAGE); + if (ret) + goto unlock; + + page = hyp_phys_to_page(phys); + switch (page->host_state) { + case PKVM_PAGE_OWNED: + WARN_ON(__host_set_page_state_range(phys, PAGE_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; + default: + ret = -EPERM; + goto unlock; + } + + WARN_ON(kvm_pgtable_stage2_map(&vm->pgt, ipa, PAGE_SIZE, phys, + pkvm_mkstate(prot, PKVM_PAGE_SHARED_BORROWED), + &vcpu->vcpu.arch.pkvm_memcache, 0)); + page->host_share_guest_count++; + +unlock: + guest_unlock_component(vm); + host_unlock_component(); + + return ret; +} diff --git a/arch/arm64/kvm/hyp/nvhe/pkvm.c b/arch/arm64/kvm/hyp/nvhe/pkvm.c index 496d186efb03..f2e363fe6b84 100644 --- a/arch/arm64/kvm/hyp/nvhe/pkvm.c +++ b/arch/arm64/kvm/hyp/nvhe/pkvm.c @@ -795,6 +795,13 @@ int __pkvm_teardown_vm(pkvm_handle_t handle) /* Push the metadata pages to the teardown memcache */ for (idx = 0; idx < hyp_vm->nr_vcpus; ++idx) { struct pkvm_hyp_vcpu *hyp_vcpu = hyp_vm->vcpus[idx]; + struct kvm_hyp_memcache *vcpu_mc = &hyp_vcpu->vcpu.arch.pkvm_memcache; + + while (vcpu_mc->nr_pages) { + void *addr = pop_hyp_memcache(vcpu_mc, hyp_phys_to_virt); + push_hyp_memcache(mc, addr, hyp_virt_to_phys); + unmap_donated_memory_noclear(addr, PAGE_SIZE); + } teardown_donated_memory(mc, hyp_vcpu, sizeof(*hyp_vcpu)); }
In preparation for handling guest stage-2 mappings at EL2, introduce a new pKVM hypercall allowing to share pages with non-protected guests. Signed-off-by: Quentin Perret <qperret@google.com> --- arch/arm64/include/asm/kvm_asm.h | 1 + arch/arm64/include/asm/kvm_host.h | 3 + arch/arm64/kvm/hyp/include/nvhe/mem_protect.h | 1 + arch/arm64/kvm/hyp/include/nvhe/memory.h | 2 + arch/arm64/kvm/hyp/nvhe/hyp-main.c | 34 +++++++++ arch/arm64/kvm/hyp/nvhe/mem_protect.c | 72 +++++++++++++++++++ arch/arm64/kvm/hyp/nvhe/pkvm.c | 7 ++ 7 files changed, 120 insertions(+)