linux-kernel - Re: [RFC PATCH 19/21] KVM: gmem: Split huge boundary leafs for punch hole of private 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]

Message-ID: <aArrh5o/WCSIZeSQ@yzhao56-desk.sh.intel.com>
Date: Fri, 25 Apr 2025 09:55:19 +0800
From: Yan Zhao <yan.y.zhao@...el.com>
To: Francesco Lavra <francescolavra.fl@...il.com>
CC: <ackerleytng@...gle.com>, <binbin.wu@...ux.intel.com>,
	<chao.p.peng@...el.com>, <dave.hansen@...el.com>, <david@...hat.com>,
	<fan.du@...el.com>, <ira.weiny@...el.com>, <isaku.yamahata@...el.com>,
	<jroedel@...e.de>, <jun.miao@...el.com>, <kirill.shutemov@...el.com>,
	<kvm@...r.kernel.org>, <linux-kernel@...r.kernel.org>,
	<michael.roth@....com>, <pbonzini@...hat.com>, <pgonda@...gle.com>,
	<quic_eberman@...cinc.com>, <rick.p.edgecombe@...el.com>,
	<seanjc@...gle.com>, <tabba@...gle.com>, <thomas.lendacky@....com>,
	<vannapurve@...gle.com>, <vbabka@...e.cz>, <x86@...nel.org>,
	<xiaoyao.li@...el.com>, <zhiquan1.li@...el.com>
Subject: Re: [RFC PATCH 19/21] KVM: gmem: Split huge boundary leafs for punch
 hole of private memory

On Thu, Apr 24, 2025 at 12:19:32PM +0200, Francesco Lavra wrote:
> On 2025-04-24 at 3:08, Yan Zhao wrote:
> > diff --git a/virt/kvm/guest_memfd.c b/virt/kvm/guest_memfd.c
> > index 4bb140e7f30d..008061734ac5 100644
> > --- a/virt/kvm/guest_memfd.c
> > +++ b/virt/kvm/guest_memfd.c
> > @@ -292,13 +292,14 @@ static struct folio *kvm_gmem_get_folio(struct
> > inode *inode, pgoff_t index, int
> >  	return folio;
> >  }
> >  
> > -static void kvm_gmem_invalidate_begin(struct kvm_gmem *gmem, pgoff_t
> > start,
> > -				      pgoff_t end)
> > +static int kvm_gmem_invalidate_begin(struct kvm_gmem *gmem, pgoff_t
> > start,
> > +				     pgoff_t end, bool need_split)
> >  {
> >  	bool flush = false, found_memslot = false;
> >  	struct kvm_memory_slot *slot;
> >  	struct kvm *kvm = gmem->kvm;
> >  	unsigned long index;
> > +	int ret = 0;
> >  
> >  	xa_for_each_range(&gmem->bindings, index, slot, start, end -
> > 1) {
> >  		pgoff_t pgoff = slot->gmem.pgoff;
> > @@ -319,14 +320,23 @@ static void kvm_gmem_invalidate_begin(struct
> > kvm_gmem *gmem, pgoff_t start,
> >  			kvm_mmu_invalidate_begin(kvm);
> >  		}
> >  
> > +		if (need_split) {
> > +			ret = kvm_split_boundary_leafs(kvm,
> > &gfn_range);
> > +			if (ret < 0)
> > +				goto out;
> > +
> > +			flush |= ret;
> > +		}
> >  		flush |= kvm_mmu_unmap_gfn_range(kvm, &gfn_range);
> >  	}
> >  
> > +out:
> >  	if (flush)
> >  		kvm_flush_remote_tlbs(kvm);
> >  
> >  	if (found_memslot)
> >  		KVM_MMU_UNLOCK(kvm);
> > +	return 0;
> 
> Should return ret, not 0
Yes, thank you for the correction!