diff options
| author | Quentin Perret <qperret@google.com> | 2022-11-10 22:02:41 +0300 |
|---|---|---|
| committer | Marc Zyngier <maz@kernel.org> | 2022-11-11 19:40:54 +0300 |
| commit | 9926cfce8dcb880255f30ab9ac930add787e1ead (patch) | |
| tree | 46a94d0137504131710e83f42b4189a8ec9b63b8 /arch/arm64/kvm/hyp/include/nvhe | |
| parent | 43c1ff8b75011bc3e3e923adf31ba815864a2494 (diff) | |
| download | linux-9926cfce8dcb880255f30ab9ac930add787e1ead.tar.xz | |
KVM: arm64: Add helpers to pin memory shared with the hypervisor at EL2
Add helpers allowing the hypervisor to check whether a range of pages
are currently shared by the host, and 'pin' them if so by blocking host
unshare operations until the memory has been unpinned.
This will allow the hypervisor to take references on host-provided
data-structures (e.g. 'struct kvm') with the guarantee that these pages
will remain in a stable state until the hypervisor decides to release
them, for example during guest teardown.
Tested-by: Vincent Donnefort <vdonnefort@google.com>
Signed-off-by: Quentin Perret <qperret@google.com>
Signed-off-by: Will Deacon <will@kernel.org>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20221110190259.26861-9-will@kernel.org
Diffstat (limited to 'arch/arm64/kvm/hyp/include/nvhe')
| -rw-r--r-- | arch/arm64/kvm/hyp/include/nvhe/mem_protect.h | 3 | ||||
| -rw-r--r-- | arch/arm64/kvm/hyp/include/nvhe/memory.h | 7 |
2 files changed, 9 insertions, 1 deletions
diff --git a/arch/arm64/kvm/hyp/include/nvhe/mem_protect.h b/arch/arm64/kvm/hyp/include/nvhe/mem_protect.h index c87b19b2d468..998bf165af71 100644 --- a/arch/arm64/kvm/hyp/include/nvhe/mem_protect.h +++ b/arch/arm64/kvm/hyp/include/nvhe/mem_protect.h @@ -69,6 +69,9 @@ int host_stage2_set_owner_locked(phys_addr_t addr, u64 size, u8 owner_id); int kvm_host_prepare_stage2(void *pgt_pool_base); void handle_host_mem_abort(struct kvm_cpu_context *host_ctxt); +int hyp_pin_shared_mem(void *from, void *to); +void hyp_unpin_shared_mem(void *from, void *to); + static __always_inline void __load_host_stage2(void) { if (static_branch_likely(&kvm_protected_mode_initialized)) diff --git a/arch/arm64/kvm/hyp/include/nvhe/memory.h b/arch/arm64/kvm/hyp/include/nvhe/memory.h index 9422900e5c6a..ab205c4d6774 100644 --- a/arch/arm64/kvm/hyp/include/nvhe/memory.h +++ b/arch/arm64/kvm/hyp/include/nvhe/memory.h @@ -55,10 +55,15 @@ static inline void hyp_page_ref_inc(struct hyp_page *p) p->refcount++; } -static inline int hyp_page_ref_dec_and_test(struct hyp_page *p) +static inline void hyp_page_ref_dec(struct hyp_page *p) { BUG_ON(!p->refcount); p->refcount--; +} + +static inline int hyp_page_ref_dec_and_test(struct hyp_page *p) +{ + hyp_page_ref_dec(p); return (p->refcount == 0); } |