[PATCH v4 07/12] ARM: KVM: fix handling of trapped 64bit coprocessor accesses

Marc Zyngier marc.zyngier at arm.com
Tue Feb 18 10:27:28 EST 2014


Commit 240e99cbd00a (ARM: KVM: Fix 64-bit coprocessor handling)
changed the way we match the 64bit coprocessor access from
user space, but didn't update the trap handler for the same
set of registers.

The effect is that a trapped 64bit access is never matched, leading
to a fault being injected into the guest. This went unnoticed as we
didn't really trap any 64bit register so far.

Placing the CRm field of the access into the CRn field of the matching
structure fixes the problem. Also update the debug feature to emit the
expected string in case of failing match.

Signed-off-by: Marc Zyngier <marc.zyngier at arm.com>
Reviewed-by: Christoffer Dall <christoffer.dall at linaro.org>
Acked-by: Catalin Marinas <catalin.marinas at arm.com>
---
 arch/arm/kvm/coproc.c | 4 ++--
 arch/arm/kvm/coproc.h | 4 ++--
 2 files changed, 4 insertions(+), 4 deletions(-)

diff --git a/arch/arm/kvm/coproc.c b/arch/arm/kvm/coproc.c
index 78c0885..126c90d 100644
--- a/arch/arm/kvm/coproc.c
+++ b/arch/arm/kvm/coproc.c
@@ -443,7 +443,7 @@ int kvm_handle_cp15_64(struct kvm_vcpu *vcpu, struct kvm_run *run)
 {
 	struct coproc_params params;
 
-	params.CRm = (kvm_vcpu_get_hsr(vcpu) >> 1) & 0xf;
+	params.CRn = (kvm_vcpu_get_hsr(vcpu) >> 1) & 0xf;
 	params.Rt1 = (kvm_vcpu_get_hsr(vcpu) >> 5) & 0xf;
 	params.is_write = ((kvm_vcpu_get_hsr(vcpu) & 1) == 0);
 	params.is_64bit = true;
@@ -451,7 +451,7 @@ int kvm_handle_cp15_64(struct kvm_vcpu *vcpu, struct kvm_run *run)
 	params.Op1 = (kvm_vcpu_get_hsr(vcpu) >> 16) & 0xf;
 	params.Op2 = 0;
 	params.Rt2 = (kvm_vcpu_get_hsr(vcpu) >> 10) & 0xf;
-	params.CRn = 0;
+	params.CRm = 0;
 
 	return emulate_cp15(vcpu, &params);
 }
diff --git a/arch/arm/kvm/coproc.h b/arch/arm/kvm/coproc.h
index 0461d5c..c5ad7ff 100644
--- a/arch/arm/kvm/coproc.h
+++ b/arch/arm/kvm/coproc.h
@@ -58,8 +58,8 @@ static inline void print_cp_instr(const struct coproc_params *p)
 {
 	/* Look, we even formatted it for you to paste into the table! */
 	if (p->is_64bit) {
-		kvm_pr_unimpl(" { CRm(%2lu), Op1(%2lu), is64, func_%s },\n",
-			      p->CRm, p->Op1, p->is_write ? "write" : "read");
+		kvm_pr_unimpl(" { CRm64(%2lu), Op1(%2lu), is64, func_%s },\n",
+			      p->CRn, p->Op1, p->is_write ? "write" : "read");
 	} else {
 		kvm_pr_unimpl(" { CRn(%2lu), CRm(%2lu), Op1(%2lu), Op2(%2lu), is32,"
 			      " func_%s },\n",
-- 
1.8.3.4




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