On Mon, 9 Aug 2021 at 16:24, Quentin Perret <[email protected]> wrote:
> We currently unmap all MMIO mappings from the host stage-2 to recycle > the pages whenever we run out. In order to make this pattern easy to > re-use from other places, factor the logic out into a dedicated macro. > While at it, apply the macro for the kvm_pgtable_stage2_set_owner() > calls. They're currently only called early on and are guaranteed to > succeed, but making them robust to the -ENOMEM case doesn't hurt and > will avoid painful debugging sessions later on. > > Reviewed-by: Fuad Tabba <[email protected]> > Signed-off-by: Quentin Perret <[email protected]> > --- > arch/arm64/kvm/hyp/nvhe/mem_protect.c | 40 +++++++++++++++------------ > 1 file changed, 22 insertions(+), 18 deletions(-) > > diff --git a/arch/arm64/kvm/hyp/nvhe/mem_protect.c > b/arch/arm64/kvm/hyp/nvhe/mem_protect.c > index d938ce95d3bd..74280a753efb 100644 > --- a/arch/arm64/kvm/hyp/nvhe/mem_protect.c > +++ b/arch/arm64/kvm/hyp/nvhe/mem_protect.c > @@ -208,6 +208,25 @@ static inline int __host_stage2_idmap(u64 start, u64 > end, > prot, &host_s2_pool); > } > > +/* > + * The pool has been provided with enough pages to cover all of memory > with > + * page granularity, but it is difficult to know how much of the MMIO > range > + * we will need to cover upfront, so we may need to 'recycle' the pages > if we > + * run out. > + */ > +#define host_stage2_try(fn, ...) \ > + ({ \ > + int __ret; \ > + hyp_assert_lock_held(&host_kvm.lock); \ > + __ret = fn(__VA_ARGS__); \ > + if (__ret == -ENOMEM) { \ > + __ret = host_stage2_unmap_dev_all(); \ > + if (!__ret) \ > + __ret = fn(__VA_ARGS__); \ > + } \ > + __ret; \ > + }) > + > static int host_stage2_idmap(u64 addr) > { > enum kvm_pgtable_prot prot = KVM_PGTABLE_PROT_R | > KVM_PGTABLE_PROT_W; > @@ -223,22 +242,7 @@ static int host_stage2_idmap(u64 addr) > if (ret) > goto unlock; > > - ret = __host_stage2_idmap(range.start, range.end, prot); > - if (ret != -ENOMEM) > - goto unlock; > - > - /* > - * The pool has been provided with enough pages to cover all of > memory > - * with page granularity, but it is difficult to know how much of > the > - * MMIO range we will need to cover upfront, so we may need to > 'recycle' > - * the pages if we run out. > - */ > - ret = host_stage2_unmap_dev_all(); > - if (ret) > - goto unlock; > - > - ret = __host_stage2_idmap(range.start, range.end, prot); > - > + ret = host_stage2_try(__host_stage2_idmap, range.start, range.end, > prot); > unlock: > hyp_spin_unlock(&host_kvm.lock); > > @@ -257,8 +261,8 @@ int __pkvm_mark_hyp(phys_addr_t start, phys_addr_t end) > return -EINVAL; > > hyp_spin_lock(&host_kvm.lock); > - ret = kvm_pgtable_stage2_set_owner(&host_kvm.pgt, start, end - > start, > - &host_s2_pool, pkvm_hyp_id); > + ret = host_stage2_try(kvm_pgtable_stage2_set_owner, &host_kvm.pgt, > + start, end - start, &host_s2_pool, > pkvm_hyp_id); > hyp_spin_unlock(&host_kvm.lock); > > return ret != -EAGAIN ? ret : 0; > -- > 2.32.0.605.g8dce9f2422-goog > > Reviewed-by: Andrew Walbran <[email protected]>
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