Messages in this thread | | | From | Andrew Walbran <> | Date | Tue, 14 Dec 2021 14:48:30 +0000 | Subject | Re: [PATCH v3 10/15] KVM: arm64: Introduce wrappers for host and hyp spin lock accessors |
| |
On Wed, 1 Dec 2021 at 17:04, 'Quentin Perret' via kernel-team <kernel-team@android.com> wrote: > > From: Will Deacon <will@kernel.org> > > In preparation for adding additional locked sections for manipulating > page-tables at EL2, introduce some simple wrappers around the host and > hypervisor locks so that it's a bit easier to read and bit more difficult > to take the wrong lock (or even take them in the wrong order). Looks good, but how does this help prevent taking locks in the wrong order?
> > Signed-off-by: Will Deacon <will@kernel.org> > Signed-off-by: Quentin Perret <qperret@google.com> > --- > arch/arm64/kvm/hyp/nvhe/mem_protect.c | 32 ++++++++++++++++++++++----- > 1 file changed, 26 insertions(+), 6 deletions(-) > > diff --git a/arch/arm64/kvm/hyp/nvhe/mem_protect.c b/arch/arm64/kvm/hyp/nvhe/mem_protect.c > index c1a90dd022b8..757dfefe3aeb 100644 > --- a/arch/arm64/kvm/hyp/nvhe/mem_protect.c > +++ b/arch/arm64/kvm/hyp/nvhe/mem_protect.c > @@ -27,6 +27,26 @@ static struct hyp_pool host_s2_pool; > > const u8 pkvm_hyp_id = 1; > > +static void host_lock_component(void) > +{ > + hyp_spin_lock(&host_kvm.lock); > +} > + > +static void host_unlock_component(void) > +{ > + hyp_spin_unlock(&host_kvm.lock); > +} > + > +static void hyp_lock_component(void) > +{ > + hyp_spin_lock(&pkvm_pgd_lock); > +} > + > +static void hyp_unlock_component(void) > +{ > + hyp_spin_unlock(&pkvm_pgd_lock); > +} > + > static void *host_s2_zalloc_pages_exact(size_t size) > { > void *addr = hyp_alloc_pages(&host_s2_pool, get_order(size)); > @@ -338,14 +358,14 @@ static int host_stage2_idmap(u64 addr) > > prot = is_memory ? PKVM_HOST_MEM_PROT : PKVM_HOST_MMIO_PROT; > > - hyp_spin_lock(&host_kvm.lock); > + host_lock_component(); > ret = host_stage2_adjust_range(addr, &range); > if (ret) > goto unlock; > > ret = host_stage2_idmap_locked(range.start, range.end - range.start, prot); > unlock: > - hyp_spin_unlock(&host_kvm.lock); > + host_unlock_component(); > > return ret; > } > @@ -369,8 +389,8 @@ int __pkvm_host_share_hyp(u64 pfn) > if (!addr_is_memory(addr)) > return -EINVAL; > > - hyp_spin_lock(&host_kvm.lock); > - hyp_spin_lock(&pkvm_pgd_lock); > + host_lock_component(); > + hyp_lock_component(); > > ret = kvm_pgtable_get_leaf(&host_kvm.pgt, addr, &pte, NULL); > if (ret) > @@ -432,8 +452,8 @@ int __pkvm_host_share_hyp(u64 pfn) > BUG_ON(ret); > > unlock: > - hyp_spin_unlock(&pkvm_pgd_lock); > - hyp_spin_unlock(&host_kvm.lock); > + hyp_unlock_component(); > + host_unlock_component(); > > return ret; > } > -- > 2.34.0.rc2.393.gf8c9666880-goog > > -- > To unsubscribe from this group and stop receiving emails from it, send an email to kernel-team+unsubscribe@android.com. >
| |