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FAILED: patch "[PATCH] MIPS: KVM: Fix ASID restoration logic" failed to apply to 3.10-stable tree

PATCH [email protected] 1 participant 1 message Dec 7, 2015

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The patch below does not apply to the 3.10-stable tree.
If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <[email protected]>.

thanks,

greg k-h

------------------ original commit in Linus's tree ------------------

Quoted 1 line

From 002374f371bd02df864cce1fe85d90dc5b292837 Mon Sep 17 00:00:00 2001

From: James Hogan <[email protected]>
Date: Wed, 11 Nov 2015 14:21:18 +0000
Subject: [PATCH] MIPS: KVM: Fix ASID restoration logic

ASID restoration on guest resume should determine the guest execution mode based on the guest Status register rather than bit 30 of the guest PC.

Fix the two places in locore.S that do this, loading the guest status from the cop0 area. Note, this assembly is specific to the trap & emulate implementation of KVM, so it doesn't need to check the supervisor bit as that mode is not implemented in the guest.

Fixes b680f70fc111 ("KVM/MIPS32: Entry point for trampolining to...")
Signed-off-by James Hogan <[email protected]>
Cc Ralf Baechle <[email protected]>
Cc Paolo Bonzini <[email protected]>
Cc Gleb Natapov <[email protected]>
Cc [email protected]
Cc [email protected]
Cc <[email protected]> # 3.10.x-
Signed-off-by Paolo Bonzini <[email protected]>
arch/mips/kvm/locore.S +10 -6
index 7bab3a4e8f7d..7e2210846b8b 100644
@@ -157,9 +157,11 @@ FEXPORT(__kvm_mips_vcpu_run)
 
 FEXPORT(__kvm_mips_load_asid)
 	/* Set the ASID for the Guest Kernel */
-	INT_SLL	t0, t0, 1	/* with kseg0 @ 0x40000000, kernel */
-			        /* addresses shift to 0x80000000 */
-	bltz	t0, 1f		/* If kernel */
+	PTR_L	t0, VCPU_COP0(k1)
+	LONG_L	t0, COP0_STATUS(t0)
+	andi	t0, KSU_USER | ST0_ERL | ST0_EXL
+	xori	t0, KSU_USER
+	bnez	t0, 1f		/* If kernel */
 	 INT_ADDIU t1, k1, VCPU_GUEST_KERNEL_ASID  /* (BD)  */
 	INT_ADDIU t1, k1, VCPU_GUEST_USER_ASID    /* else user */
 1:

@@ -474,9 +476,11 @@ __kvm_mips_return_to_guest:
 	mtc0	t0, CP0_EPC
 
 	/* Set the ASID for the Guest Kernel */
-	INT_SLL	t0, t0, 1	/* with kseg0 @ 0x40000000, kernel */
-				/* addresses shift to 0x80000000 */
-	bltz	t0, 1f		/* If kernel */
+	PTR_L	t0, VCPU_COP0(k1)
+	LONG_L	t0, COP0_STATUS(t0)
+	andi	t0, KSU_USER | ST0_ERL | ST0_EXL
+	xori	t0, KSU_USER
+	bnez	t0, 1f		/* If kernel */
 	 INT_ADDIU t1, k1, VCPU_GUEST_KERNEL_ASID  /* (BD)  */
 	INT_ADDIU t1, k1, VCPU_GUEST_USER_ASID    /* else user */
 1: