Le 06/02/2020 à 04:08, Leonardo Bras a écrit :
Applies the new functions used for tracking lockless pgtable walks on
kvmppc_e500_shadow_map().
Fixes the place where local_irq_restore() is called: previously, if ptep
was NULL, local_irq_restore() would never be called.
local_irq_{save,restore} is already inside {begin,end}_lockless_pgtbl_walk,
so there is no need to repeat it here.
Variable that saves the irq mask was renamed from flags to irq_mask so it
doesn't lose meaning now it's not directly passed to local_irq_* functions.
Signed-off-by: Leonardo Bras <leonardo@xxxxxxxxxxxxx>
---
arch/powerpc/kvm/e500_mmu_host.c | 9 +++++----
1 file changed, 5 insertions(+), 4 deletions(-)
diff --git a/arch/powerpc/kvm/e500_mmu_host.c b/arch/powerpc/kvm/e500_mmu_host.c
index 425d13806645..3dcf11f77256 100644
--- a/arch/powerpc/kvm/e500_mmu_host.c
+++ b/arch/powerpc/kvm/e500_mmu_host.c
@@ -336,7 +336,7 @@ static inline int kvmppc_e500_shadow_map(struct kvmppc_vcpu_e500 *vcpu_e500,
pte_t *ptep;
unsigned int wimg = 0;
pgd_t *pgdir;
- unsigned long flags;
+ unsigned long irq_mask;
/* used to check for invalidations in progress */
mmu_seq = kvm->mmu_notifier_seq;
@@ -473,7 +473,7 @@ static inline int kvmppc_e500_shadow_map(struct kvmppc_vcpu_e500 *vcpu_e500,
* We are holding kvm->mmu_lock so a notifier invalidate
* can't run hence pfn won't change.
*/
- local_irq_save(flags);
+ irq_mask = begin_lockless_pgtbl_walk();
ptep = find_linux_pte(pgdir, hva, NULL, NULL);
if (ptep) {
pte_t pte = READ_ONCE(*ptep);
@@ -481,15 +481,16 @@ static inline int kvmppc_e500_shadow_map(struct kvmppc_vcpu_e500 *vcpu_e500,
if (pte_present(pte)) {
wimg = (pte_val(pte) >> PTE_WIMGE_SHIFT) &
MAS2_WIMGE_MASK;
- local_irq_restore(flags);
} else {
- local_irq_restore(flags);
+ end_lockless_pgtbl_walk(irq_mask);
pr_err_ratelimited("%s: pte not present: gfn %lx,pfn %lx\n",
__func__, (long)gfn, pfn);
ret = -EINVAL;
goto out;
}
}
+ end_lockless_pgtbl_walk(irq_mask);
+
I don't really like unbalanced begin/end.
Something like the following would be cleaner:
begin_lockless_pgtbl_walk()
ptep = find()
if (ptep) {
pte = READ_ONCE()
if (pte_present(pte))
wing=
else
ret = -EINVAL;
}
end_lockless_pgtbl_walk()
if (ret) {
pr_err_rate...()
goto out;
}
kvmppc_e500_ref_setup(ref, gtlbe, pfn, wimg);
kvmppc_e500_setup_stlbe(&vcpu_e500->vcpu, gtlbe, tsize,
Christophe
