[PATCH 4.14 030/122] KVM: PPC: Inform the userspace about TCE update failures

From: Greg Kroah-Hartman
Date: Fri Nov 22 2019 - 05:52:19 EST


From: Alexey Kardashevskiy <aik@xxxxxxxxx>

[ Upstream commit f7960e299f13f069d6f3d4e157d91bfca2669677 ]

We return H_TOO_HARD from TCE update handlers when we think that
the next handler (realmode -> virtual mode -> user mode) has a chance to
handle the request; H_HARDWARE/H_CLOSED otherwise.

This changes the handlers to return H_TOO_HARD on every error giving
the userspace an opportunity to handle any request or at least log
them all.

Signed-off-by: Alexey Kardashevskiy <aik@xxxxxxxxx>
Reviewed-by: David Gibson <david@xxxxxxxxxxxxxxxxxxxxx>
Signed-off-by: Michael Ellerman <mpe@xxxxxxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
arch/powerpc/kvm/book3s_64_vio.c | 8 ++++----
arch/powerpc/kvm/book3s_64_vio_hv.c | 6 +++---
2 files changed, 7 insertions(+), 7 deletions(-)

diff --git a/arch/powerpc/kvm/book3s_64_vio.c b/arch/powerpc/kvm/book3s_64_vio.c
index 2c6cce8e7cfd0..5e44462960213 100644
--- a/arch/powerpc/kvm/book3s_64_vio.c
+++ b/arch/powerpc/kvm/book3s_64_vio.c
@@ -404,7 +404,7 @@ static long kvmppc_tce_iommu_unmap(struct kvm *kvm,
long ret;

if (WARN_ON_ONCE(iommu_tce_xchg(tbl, entry, &hpa, &dir)))
- return H_HARDWARE;
+ return H_TOO_HARD;

if (dir == DMA_NONE)
return H_SUCCESS;
@@ -434,15 +434,15 @@ long kvmppc_tce_iommu_map(struct kvm *kvm, struct iommu_table *tbl,
return H_TOO_HARD;

if (WARN_ON_ONCE(mm_iommu_ua_to_hpa(mem, ua, tbl->it_page_shift, &hpa)))
- return H_HARDWARE;
+ return H_TOO_HARD;

if (mm_iommu_mapped_inc(mem))
- return H_CLOSED;
+ return H_TOO_HARD;

ret = iommu_tce_xchg(tbl, entry, &hpa, &dir);
if (WARN_ON_ONCE(ret)) {
mm_iommu_mapped_dec(mem);
- return H_HARDWARE;
+ return H_TOO_HARD;
}

if (dir != DMA_NONE)
diff --git a/arch/powerpc/kvm/book3s_64_vio_hv.c b/arch/powerpc/kvm/book3s_64_vio_hv.c
index 23d6d1592f117..c75e5664fe3d8 100644
--- a/arch/powerpc/kvm/book3s_64_vio_hv.c
+++ b/arch/powerpc/kvm/book3s_64_vio_hv.c
@@ -264,14 +264,14 @@ static long kvmppc_rm_tce_iommu_map(struct kvm *kvm, struct iommu_table *tbl,

if (WARN_ON_ONCE_RM(mm_iommu_ua_to_hpa_rm(mem, ua, tbl->it_page_shift,
&hpa)))
- return H_HARDWARE;
+ return H_TOO_HARD;

pua = (void *) vmalloc_to_phys(pua);
if (WARN_ON_ONCE_RM(!pua))
return H_HARDWARE;

if (WARN_ON_ONCE_RM(mm_iommu_mapped_inc(mem)))
- return H_CLOSED;
+ return H_TOO_HARD;

ret = iommu_tce_xchg_rm(tbl, entry, &hpa, &dir);
if (ret) {
@@ -448,7 +448,7 @@ long kvmppc_rm_h_put_tce_indirect(struct kvm_vcpu *vcpu,

rmap = (void *) vmalloc_to_phys(rmap);
if (WARN_ON_ONCE_RM(!rmap))
- return H_HARDWARE;
+ return H_TOO_HARD;

/*
* Synchronize with the MMU notifier callbacks in
--
2.20.1