NothingOSS/android_kernel_msm-6.1_nothing_sm7635
1
0
Fork 0
Code Issues Pull requests Projects Releases Packages Wiki Activity Actions

ANDROID: KVM: arm64: Restrict host-to-hyp MMIO donations

Browse source 
Nothing currently prevents the donation of an MMIO region to the
hypervisor for backing e.g. guest stage-2 page-tables, tracing buffers,
hyp vm and vcpu metadata, or any other donation to EL2. However, the
only confirmed use-case for MMIO donations are for protecting the IOMMU
registers as well as for vendor module usage.

Restrict the donation of MMIO regions to these two paths only by
introducing a new helper function.

Bug: 264070847
Change-Id: I914508fb3e3547fcfabca8557bdf7948cb796099
Signed-off-by: Quentin Perret <qperret@google.com>
This commit is contained in:
Quentin Perret 2023-06-07 13:50:26 +00:00 • committed by Carlos Llamas
parent f5f8c19f6c
commit b7aff5c603
3 changed files with 17 additions and 1 deletions
Download patch file Download diff file Expand all files Collapse all files

1
arch/arm64/kvm/hyp/include/nvhe/mem_protect.h
View file

@ -72,6 +72,7 @@ int __pkvm_host_share_hyp(u64 pfn);
int __pkvm_host_unshare_hyp(u64 pfn);
int __pkvm_host_reclaim_page(struct pkvm_hyp_vm *vm, u64 pfn, u64 ipa);
int __pkvm_host_donate_hyp(u64 pfn, u64 nr_pages);
int ___pkvm_host_donate_hyp(u64 pfn, u64 nr_pages, bool accept_mmio);
int __pkvm_host_donate_hyp_locked(u64 pfn, u64 nr_pages);
int __pkvm_hyp_donate_host(u64 pfn, u64 nr_pages);
int __pkvm_host_share_guest(u64 pfn, u64 gfn, struct pkvm_hyp_vcpu *vcpu);

10
arch/arm64/kvm/hyp/nvhe/mem_protect.c
View file

@ -1942,8 +1942,18 @@ int __pkvm_host_unshare_hyp(u64 pfn)
int __pkvm_host_donate_hyp(u64 pfn, u64 nr_pages)
{
return ___pkvm_host_donate_hyp(pfn, nr_pages, false);
}
int ___pkvm_host_donate_hyp(u64 pfn, u64 nr_pages, bool accept_mmio)
{
phys_addr_t start = hyp_pfn_to_phys(pfn);
phys_addr_t end = start + (nr_pages << PAGE_SHIFT);
int ret;
if (!accept_mmio && !range_is_memory(start, end))
return -EPERM;
host_lock_component();
ret = __pkvm_host_donate_hyp_locked(pfn, nr_pages);
host_unlock_component();

7
arch/arm64/kvm/hyp/nvhe/modules.c
View file

@ -77,6 +77,11 @@ void __pkvm_close_module_registration(void)
*/
}
static int __pkvm_module_host_donate_hyp(u64 pfn, u64 nr_pages)
{
return ___pkvm_host_donate_hyp(pfn, nr_pages, true);
}
const struct pkvm_module_ops module_ops = {
.create_private_mapping = __pkvm_create_private_mapping,
.alloc_module_va = __pkvm_alloc_module_va,
@ -99,7 +104,7 @@ const struct pkvm_module_ops module_ops = {
.register_illegal_abt_notifier = __pkvm_register_illegal_abt_notifier,
.register_psci_notifier = __pkvm_register_psci_notifier,
.register_hyp_panic_notifier = __pkvm_register_hyp_panic_notifier,
.host_donate_hyp = __pkvm_host_donate_hyp,
.host_donate_hyp = __pkvm_module_host_donate_hyp,
.hyp_donate_host = __pkvm_hyp_donate_host,
.host_share_hyp = __pkvm_host_share_hyp,
.host_unshare_hyp = __pkvm_host_unshare_hyp,