tmakin/ack-tegra
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

BACKPORT: FROMLIST: KVM: arm64: pkvm: Add __pkvm_host_add_remove_page()

Browse Source 
Add a small helper to remove and add back a page from the host stage-2.
This will be used to temporarily unmap a piece of shared sram (device
memory) from the host while we handle a SCMI request, preventing the
host from modifying the request after it is verified.

Link: https://lore.kernel.org/all/20241212180423.1578358-22-smostafa@google.com/

Bug: 357781595
Bug: 384432312

Change-Id: I4f6625c8c435b945821c934d1ad435ba1fd66b39
Signed-off-by: Jean-Philippe Brucker <jean-philippe@linaro.org>
Signed-off-by: Mostafa Saleh <smostafa@google.com>
This commit is contained in:
Jean-Philippe Brucker
2024-12-12 18:03:45 +00:00
committed by Mostafa Saleh
parent 2e3d19be3e
commit 61dced62ff
2 changed files with 18 additions and 0 deletions
Download Patch File Download Diff File Expand all files Collapse all files
arch/arm64/kvm/hyp/include/nvhe/mem_protect.h
+1
View File
@@ -62,6 +62,7 @@ int __pkvm_guest_relinquish_to_host(struct pkvm_hyp_vcpu *vcpu,
u64 ipa, u64 *ppa);
int __pkvm_host_use_dma(u64 phys_addr, size_t size);
int __pkvm_host_unuse_dma(u64 phys_addr, size_t size);
int __pkvm_host_add_remove_page(u64 pfn, bool remove);
bool addr_is_memory(phys_addr_t phys);
int host_stage2_idmap_locked(phys_addr_t addr, u64 size, enum kvm_pgtable_prot prot);
arch/arm64/kvm/hyp/nvhe/mem_protect.c
+17
View File
@@ -2592,3 +2592,20 @@ int host_stage2_get_leaf(phys_addr_t phys, kvm_pte_t *ptep, s8 *level)
return ret;
}
/*
* Temporarily unmap a page from the host stage-2, if @remove is true, or put it
* back. After restoring the ownership to host, the page will be lazy-mapped.
*/
int __pkvm_host_add_remove_page(u64 pfn, bool remove)
{
int ret;
u64 host_addr = hyp_pfn_to_phys(pfn);
u8 owner = remove ? PKVM_ID_HYP : PKVM_ID_HOST;
host_lock_component();
ret = host_stage2_set_owner_locked(host_addr, PAGE_SIZE, owner);
host_unlock_component();
return ret;
}