linux-kernel - Re: [RFC PATCH 2/8] KVM: Add KVM_MAP_MEMORY vcpu ioctl to pre-populate guest memory

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: Windows password security audit tool. GUI, reports in PDF.

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

Date: Wed, 6 Mar 2024 18:52:52 -0800
From: Isaku Yamahata <isaku.yamahata@...ux.intel.com>
To: David Matlack <dmatlack@...gle.com>
Cc: isaku.yamahata@...el.com, kvm@...r.kernel.org, isaku.yamahata@...il.com,
	linux-kernel@...r.kernel.org,
	Sean Christopherson <seanjc@...gle.com>,
	Paolo Bonzini <pbonzini@...hat.com>,
	Michael Roth <michael.roth@....com>,
	Federico Parola <federico.parola@...ito.it>,
	isaku.yamahata@...ux.intel.com
Subject: Re: [RFC PATCH 2/8] KVM: Add KVM_MAP_MEMORY vcpu ioctl to
 pre-populate guest memory

On Wed, Mar 06, 2024 at 04:49:19PM -0800,
David Matlack <dmatlack@...gle.com> wrote:

> > +			cond_resched();
> > +
> > +		r = kvm_arch_vcpu_map_memory(vcpu, mapping);
> > +		if (r)
> > +			break;
> > +
> > +		added = true;
> > +	}
> > +
> > +	srcu_read_unlock(&vcpu->kvm->srcu, idx);
> > +	vcpu_put(vcpu);
> > +
> > +	if (added && mapping->nr_pages > 0)
> > +		r = -EAGAIN;
> 
> This can overwrite the return value from kvm_arch_vcpu_map_memory().

This is to convert ERESTART into EAGAIN.  I'll drop this check
and document EINTR so that caller should be aware of partial population.
-- 
Isaku Yamahata <isaku.yamahata@...ux.intel.com>