96df226 "KVM: PPC: Book3S PR: Preserve storage control bits" added WIMG
bits preserving but it missed 2 special cases:
- a magic page in kvmppc_mmu_book3s_64_xlate() and
- guest real mode in kvmppc_handle_pagefault().
For these ptes WIMG were 0 and pHyp failed on these causing a guest to
stop in the very beginning at NIP=0x100 (due to bd9166ffe
"KVM: PPC: Book3S PR: Exit KVM on failed mapping").
This initializes WIMG to non-zero value HPTE_R_M. The value is chosen
as (0x192 & HPTE_R_WIMG); 0x192 is a magic value from
kvmppc_mmu_map_page().
Fixes: 96df226 "KVM: PPC: Book3S PR: Preserve storage control bits"
Signed-off-by: Alexey Kardashevskiy <aik@xxxxxxxxx>
---
This indeed fixes PR KVM + VFIO under pHyp but selection of HPTE_R_M
is arguable.
---
arch/powerpc/kvm/book3s_64_mmu.c | 1 +
arch/powerpc/kvm/book3s_pr.c | 1 +
2 files changed, 2 insertions(+)
diff --git a/arch/powerpc/kvm/book3s_64_mmu.c b/arch/powerpc/kvm/book3s_64_mmu.c
index 29ebe2f..a93d719 100644
--- a/arch/powerpc/kvm/book3s_64_mmu.c
+++ b/arch/powerpc/kvm/book3s_64_mmu.c
@@ -235,6 +235,7 @@ static int kvmppc_mmu_book3s_64_xlate(struct kvm_vcpu *vcpu, gva_t eaddr,
gpte->may_read = true;
gpte->may_write = true;
gpte->page_size = MMU_PAGE_4K;
+ gpte->wimg = HPTE_R_M;
return 0;
}
diff --git a/arch/powerpc/kvm/book3s_pr.c b/arch/powerpc/kvm/book3s_pr.c
index 69a0944..0152efe 100644
--- a/arch/powerpc/kvm/book3s_pr.c
+++ b/arch/powerpc/kvm/book3s_pr.c
@@ -557,6 +557,7 @@ int kvmppc_handle_pagefault(struct kvm_run *run, struct kvm_vcpu *vcpu,
pte.eaddr = eaddr;
pte.vpage = eaddr >> 12;
pte.page_size = MMU_PAGE_64K;
+ pte.wimg = HPTE_R_M;
}
switch (kvmppc_get_msr(vcpu) & (MSR_DR|MSR_IR)) {
--
2.11.0
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