Patchwork [3.5.y.z,extended,stable] Patch "KVM: PPC: Emulate dcbf" has been added to staging queue

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Submitter Herton Ronaldo Krzesinski
Date Jan. 30, 2013, 9:57 p.m.
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Download mbox | patch
Permalink /patch/217034/
State New
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Herton Ronaldo Krzesinski - Jan. 30, 2013, 9:57 p.m.
This is a note to let you know that I have just added a patch titled

    KVM: PPC: Emulate dcbf

to the linux-3.5.y-queue branch of the 3.5.y.z extended stable tree 
which can be found at:;a=shortlog;h=refs/heads/linux-3.5.y-queue

If you, or anyone else, feels it should not be added to this tree, please 
reply to this email.

For more information about the 3.5.y.z tree, see



From a20e33977677517504f2968951ce29fd9b27753d Mon Sep 17 00:00:00 2001
From: Alexander Graf <>
Date: Thu, 17 Jan 2013 13:50:25 +0100
Subject: [PATCH] KVM: PPC: Emulate dcbf

commit d3286144c92ec876da9e30320afa875699b7e0f1 upstream.

Guests can trigger MMIO exits using dcbf. Since we don't emulate cache
incoherent MMIO, just do nothing and move on.

Reported-by: Ben Collins <>
Signed-off-by: Alexander Graf <>
Tested-by: Ben Collins <>
[ herton: adjust context ]
Signed-off-by: Herton Ronaldo Krzesinski <>
 arch/powerpc/kvm/emulate.c |    2 ++
 1 file changed, 2 insertions(+)



diff --git a/arch/powerpc/kvm/emulate.c b/arch/powerpc/kvm/emulate.c
index f90e86d..d382c91 100644
--- a/arch/powerpc/kvm/emulate.c
+++ b/arch/powerpc/kvm/emulate.c
@@ -39,6 +39,7 @@ 
 #define OP_31_XOP_TRAP      4
 #define OP_31_XOP_LWZX      23
 #define OP_31_XOP_TRAP_64   68
+#define OP_31_XOP_DCBF      86
 #define OP_31_XOP_LBZX      87
 #define OP_31_XOP_STWX      151
 #define OP_31_XOP_STBX      215
@@ -351,6 +352,7 @@  int kvmppc_emulate_instruction(struct kvm_run *run, struct kvm_vcpu *vcpu)
 			kvmppc_set_exit_type(vcpu, EMULATED_MTSPR_EXITS);

+		case OP_31_XOP_DCBF:
 		case OP_31_XOP_DCBI:
 			/* Do nothing. The guest is performing dcbi because
 			 * hardware DMA is not snooped by the dcache, but