[PATCH v2 27/30] KVM: MIPS/Emulate: Fix CACHE emulation for EVA hosts

From: James Hogan <james.hogan@imgtec.com>
To: <linux-mips@linux-mips.org>
Cc: "James Hogan" <james.hogan@imgtec.com>,
	"Paolo Bonzini" <pbonzini@redhat.com>,
	"Radim Krčmář" <rkrcmar@redhat.com>,
	"Ralf Baechle" <ralf@linux-mips.org>,
	kvm@vger.kernel.org
Subject: [PATCH v2 27/30] KVM: MIPS/Emulate: Fix CACHE emulation for EVA hosts
Date: Thu, 2 Feb 2017 12:04:40 +0000	[thread overview]
Message-ID: <c385db5b00ed2223c500271231626c4d5be84598.1486036366.git-series.james.hogan@imgtec.com> (raw)
In-Reply-To: <cover.e37f86dece46fc3ed00a075d68119cab361cda8e.1486036366.git-series.james.hogan@imgtec.com>

Use protected_writeback_dcache_line() instead of flush_dcache_line(),
and protected_flush_icache_line() instead of flush_icache_line(), so
that CACHEE (the EVA variant) is used on EVA host kernels.

Without this, guest floating point branch delay slot emulation via a
trampoline on the user stack fails on EVA host kernels due to failure of
the icache sync, resulting in the break instruction getting skipped and
execution from the stack.

Signed-off-by: James Hogan <james.hogan@imgtec.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: "Radim Krčmář" <rkrcmar@redhat.com>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: linux-mips@linux-mips.org
Cc: kvm@vger.kernel.org
---
 arch/mips/kvm/emulate.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/arch/mips/kvm/emulate.c b/arch/mips/kvm/emulate.c
index 3ced662e012e..9ac8e45017ce 100644
--- a/arch/mips/kvm/emulate.c
+++ b/arch/mips/kvm/emulate.c
@@ -1792,7 +1792,7 @@ enum emulation_result kvm_mips_emulate_cache(union mips_instruction inst,
 skip_fault:
 	/* XXXKYMA: Only a subset of cache ops are supported, used by Linux */
 	if (op_inst == Hit_Writeback_Inv_D || op_inst == Hit_Invalidate_D) {
-		flush_dcache_line(va);
+		protected_writeback_dcache_line(va);
 
 #ifdef CONFIG_KVM_MIPS_DYN_TRANS
 		/*
@@ -1802,8 +1802,8 @@ enum emulation_result kvm_mips_emulate_cache(union mips_instruction inst,
 		kvm_mips_trans_cache_va(inst, opc, vcpu);
 #endif
 	} else if (op_inst == Hit_Invalidate_I) {
-		flush_dcache_line(va);
-		flush_icache_line(va);
+		protected_writeback_dcache_line(va);
+		protected_flush_icache_line(va);
 
 #ifdef CONFIG_KVM_MIPS_DYN_TRANS
 		/* Replace the CACHE instruction, with a SYNCI */
-- 
git-series 0.8.10
