2019-09-23 10:16:58

by Leonardo Bras

[permalink] [raw]
Subject: [PATCH v2 07/11] powerpc/kvm/e500: Applies counting method to monitor lockless pgtbl walks

Applies the counting-based method for monitoring lockless pgtable walks on
kvmppc_e500_shadow_map().

Signed-off-by: Leonardo Bras <[email protected]>
---
arch/powerpc/kvm/e500_mmu_host.c | 4 ++++
1 file changed, 4 insertions(+)

diff --git a/arch/powerpc/kvm/e500_mmu_host.c b/arch/powerpc/kvm/e500_mmu_host.c
index 321db0fdb9db..a1b8bfe20bc8 100644
--- a/arch/powerpc/kvm/e500_mmu_host.c
+++ b/arch/powerpc/kvm/e500_mmu_host.c
@@ -473,6 +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.
*/
+ start_lockless_pgtbl_walk(kvm->mm);
local_irq_save(flags);
ptep = find_linux_pte(pgdir, hva, NULL, NULL);
if (ptep) {
@@ -484,12 +485,15 @@ static inline int kvmppc_e500_shadow_map(struct kvmppc_vcpu_e500 *vcpu_e500,
local_irq_restore(flags);
} else {
local_irq_restore(flags);
+ end_lockless_pgtbl_walk(kvm->mm);
pr_err_ratelimited("%s: pte not present: gfn %lx,pfn %lx\n",
__func__, (long)gfn, pfn);
ret = -EINVAL;
goto out;
}
}
+ end_lockless_pgtbl_walk(kvm->mm);
+
kvmppc_e500_ref_setup(ref, gtlbe, pfn, wimg);

kvmppc_e500_setup_stlbe(&vcpu_e500->vcpu, gtlbe, tsize,
--
2.20.1