From: Jiri Slaby <jslaby@suse.cz>
Date: Wed, 9 Nov 2016 21:15:57 +0000 (+0100)
Subject: Revert "KVM: MIPS: Drop other CPU ASIDs on guest MMU changes"
X-Git-Tag: v3.12.68~126
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=f668f2eee98250a2073a4beafdb7f6d1e21c528e;p=thirdparty%2Fkernel%2Fstable.git

Revert "KVM: MIPS: Drop other CPU ASIDs on guest MMU changes"

This reverts commit 168e5ebbd63eaf2557b5e37be1afb8c143de2380, which is
upstream commit 91e4f1b6073dd680d86cdb7e42d7cccca9db39d8. It caused
build failures as it was improperly backported. New version is
approaching, so revert this bad one.

Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Cc: James Hogan <james.hogan@imgtec.com>
---

diff --git a/arch/mips/kvm/kvm_mips_emul.c b/arch/mips/kvm/kvm_mips_emul.c
index 8ab9958767bb5..9f7643874fbad 100644
--- a/arch/mips/kvm/kvm_mips_emul.c
+++ b/arch/mips/kvm/kvm_mips_emul.c
@@ -310,47 +310,6 @@ enum emulation_result kvm_mips_emul_tlbr(struct kvm_vcpu *vcpu)
 	return er;
 }
 
-/**
- * kvm_mips_invalidate_guest_tlb() - Indicates a change in guest MMU map.
- * @vcpu:	VCPU with changed mappings.
- * @tlb:	TLB entry being removed.
- *
- * This is called to indicate a single change in guest MMU mappings, so that we
- * can arrange TLB flushes on this and other CPUs.
- */
-static void kvm_mips_invalidate_guest_tlb(struct kvm_vcpu *vcpu,
-					  struct kvm_mips_tlb *tlb)
-{
-	int cpu, i;
-	bool user;
-
-	/* No need to flush for entries which are already invalid */
-	if (!((tlb->tlb_lo[0] | tlb->tlb_lo[1]) & ENTRYLO_V))
-		return;
-	/* User address space doesn't need flushing for KSeg2/3 changes */
-	user = tlb->tlb_hi < KVM_GUEST_KSEG0;
-
-	preempt_disable();
-
-	/*
-	 * Probe the shadow host TLB for the entry being overwritten, if one
-	 * matches, invalidate it
-	 */
-	kvm_mips_host_tlb_inv(vcpu, tlb->tlb_hi);
-
-	/* Invalidate the whole ASID on other CPUs */
-	cpu = smp_processor_id();
-	for_each_possible_cpu(i) {
-		if (i == cpu)
-			continue;
-		if (user)
-			vcpu->arch.guest_user_asid[i] = 0;
-		vcpu->arch.guest_kernel_asid[i] = 0;
-	}
-
-	preempt_enable();
-}
-
 /* Write Guest TLB Entry @ Index */
 enum emulation_result kvm_mips_emul_tlbwi(struct kvm_vcpu *vcpu)
 {
@@ -373,8 +332,8 @@ enum emulation_result kvm_mips_emul_tlbwi(struct kvm_vcpu *vcpu)
 
 	tlb = &vcpu->arch.guest_tlb[index];
 #if 1
-
-	kvm_mips_invalidate_guest_tlb(vcpu, tlb);
+	/* Probe the shadow host TLB for the entry being overwritten, if one matches, invalidate it */
+	kvm_mips_host_tlb_inv(vcpu, tlb->tlb_hi);
 #endif
 
 	tlb->tlb_mask = kvm_read_c0_guest_pagemask(cop0);
@@ -415,7 +374,8 @@ enum emulation_result kvm_mips_emul_tlbwr(struct kvm_vcpu *vcpu)
 	tlb = &vcpu->arch.guest_tlb[index];
 
 #if 1
-	kvm_mips_invalidate_guest_tlb(vcpu, tlb);
+	/* Probe the shadow host TLB for the entry being overwritten, if one matches, invalidate it */
+	kvm_mips_host_tlb_inv(vcpu, tlb->tlb_hi);
 #endif
 
 	tlb->tlb_mask = kvm_read_c0_guest_pagemask(cop0);
@@ -459,7 +419,6 @@ kvm_mips_emulate_CP0(uint32_t inst, uint32_t *opc, uint32_t cause,
 	int32_t rt, rd, copz, sel, co_bit, op;
 	uint32_t pc = vcpu->arch.pc;
 	unsigned long curr_pc;
-	int cpu, i;
 
 	/*
 	 * Update PC and hold onto current PC in case there is
@@ -579,16 +538,8 @@ kvm_mips_emulate_CP0(uint32_t inst, uint32_t *opc, uint32_t cause,
 					     ASID_MASK,
 					     vcpu->arch.gprs[rt] & ASID_MASK);
 
-					preempt_disable();
 					/* Blow away the shadow host TLBs */
 					kvm_mips_flush_host_tlb(1);
-					cpu = smp_processor_id();
-					for_each_possible_cpu(i)
-						if (i != cpu) {
-							vcpu->arch.guest_user_asid[i] = 0;
-							vcpu->arch.guest_kernel_asid[i] = 0;
-						}
-					preempt_enable();
 				}
 				kvm_write_c0_guest_entryhi(cop0,
 							   vcpu->arch.gprs[rt]);