linux-kernel - Re: [PATCH v1 2/3] kvm: svm: Add kvm_fast_pio

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite for Android: free password hash cracker in your pocket

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <63d4112c-71c4-9d6f-60dc-c5a71c03df7a@redhat.com>
Date:   Mon, 21 Nov 2016 15:50:29 +0100
From:   Paolo Bonzini <pbonzini@...hat.com>
To:     Brijesh Singh <brijesh.singh@....com>, kvm@...r.kernel.org
Cc:     Thomas.Lendacky@....com, rkrcmar@...hat.com, joro@...tes.org,
        x86@...nel.org, linux-kernel@...r.kernel.org, mingo@...hat.com,
        hpa@...or.com, tglx@...utronix.de, bp@...e.de
Subject: Re: [PATCH v1 2/3] kvm: svm: Add kvm_fast_pio_in support



On 14/11/2016 23:15, Brijesh Singh wrote:
> +	/* For size less than 4 we merge, else we zero extend */
> +	val = (size < 4) ? kvm_register_read(vcpu, VCPU_REGS_RAX) : 0;

Are you sure it shouldn't always zero extend the high 32-bits?  So "val"
should be declared as u32.

Paolo

> +	ret = emulator_pio_in_emulated(&vcpu->arch.emulate_ctxt, size, port,
> +				       &val, 1);
> +	if (ret) {
> +		kvm_register_write(vcpu, VCPU_REGS_RAX, val);
> +		return ret;
> +	}