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Commit a449c7aa authored by Nadav Amit's avatar Nadav Amit Committed by Paolo Bonzini
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KVM: x86: Hypercall handling does not considers opsize correctly 



Currently, the hypercall handling routine only considers LME as an indication
to whether the guest uses 32/64-bit mode. This is incosistent with hyperv
hypercalls handling and against the common sense of considering cs.l as well.
This patch uses is_64_bit_mode instead of is_long_mode for that matter. In
addition, the result is masked in respect to the guest execution mode. Last, it
changes kvm_hv_hypercall to use is_64_bit_mode as well to simplify the code.

Signed-off-by: default avatarNadav Amit <namit@cs.technion.ac.il>
Signed-off-by: default avatarPaolo Bonzini <pbonzini@redhat.com>
parent 5777392e

arch/x86/kvm/x86.c

+6 −5
Original line number Diff line number Diff line
@@ -5669,7 +5669,6 @@ int kvm_hv_hypercall(struct kvm_vcpu *vcpu) 
	u64 param, ingpa, outgpa, ret;

	uint16_t code, rep_idx, rep_cnt, res = HV_STATUS_SUCCESS, rep_done = 0;

	bool fast, longmode;

	int cs_db, cs_l;



	/*

	 * hypercall generates UD from non zero cpl and real mode
@@ -5680,8 +5679,7 @@ int kvm_hv_hypercall(struct kvm_vcpu *vcpu) 
		return 0;

	}



	kvm_x86_ops->get_cs_db_l_bits(vcpu, &cs_db, &cs_l);

	longmode = is_long_mode(vcpu) && cs_l == 1;

	longmode = is_64_bit_mode(vcpu);



	if (!longmode) {

		param = ((u64)kvm_register_read(vcpu, VCPU_REGS_RDX) << 32) |
@@ -5746,7 +5744,7 @@ static void kvm_pv_kick_cpu_op(struct kvm *kvm, unsigned long flags, int apicid) 
int kvm_emulate_hypercall(struct kvm_vcpu *vcpu)

{

	unsigned long nr, a0, a1, a2, a3, ret;

	int r = 1;

	int op_64_bit, r = 1;



	if (kvm_hv_hypercall_enabled(vcpu->kvm))

		return kvm_hv_hypercall(vcpu);
@@ -5759,7 +5757,8 @@ int kvm_emulate_hypercall(struct kvm_vcpu *vcpu) 


	trace_kvm_hypercall(nr, a0, a1, a2, a3);



	if (!is_long_mode(vcpu)) {

	op_64_bit = is_64_bit_mode(vcpu);

	if (!op_64_bit) {

		nr &= 0xFFFFFFFF;

		a0 &= 0xFFFFFFFF;

		a1 &= 0xFFFFFFFF;
@@ -5785,6 +5784,8 @@ int kvm_emulate_hypercall(struct kvm_vcpu *vcpu) 
		break;

	}

out:

	if (!op_64_bit)

		ret = (u32)ret;

	kvm_register_write(vcpu, VCPU_REGS_RAX, ret);

	++vcpu->stat.hypercalls;

	return r;