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From: Paolo Bonzini <pbonzini@redhat.com>
To: harry harry <hiharryharryharry@gmail.com>,
	Sean Christopherson <sean.j.christopherson@intel.com>
Cc: Maxim Levitsky <mlevitsk@redhat.com>,
	qemu-devel@nongnu.org, mathieu.tarral@protonmail.com,
	stefanha@redhat.com, libvir-list@redhat.com, kvm@vger.kernel.org
Subject: Re: Why guest physical addresses are not the same as the corresponding host virtual addresses in QEMU/KVM? Thanks!
Date: Wed, 14 Oct 2020 10:28:05 +0200	[thread overview]
Message-ID: <626a8667-be00-96b7-f21d-1ec7648ee1e6@redhat.com> (raw)
In-Reply-To: <CA+-xGqO37RzQDg5dnE_3NWMp6+u2L02GQDqoSr3RdedoMBugrg@mail.gmail.com>

On 14/10/20 00:40, harry harry wrote:
> Q1: Is there any file like ``/proc/pid/pagemap'' to record the
> mappings between GPAs and HVAs in the host OS?

No, there isn't.

> Q2: Seems that there might be extra overhead (e.g., synchronization
> between EPT tables and host regular page tables; maintaining extra
> regular page tables and data structures), which is caused by the extra
> translation between GPAs to HVAs via memslots. Why doesn't KVM
> directly use GPAs as HVAs and leverage extended/nested page tables to
> translate HVAs (i.e., GPAs) to HPAs?

See my other answer.  What you are saying is simply not possible.

Paolo


  reply	other threads:[~2020-10-14  8:28 UTC|newest]

Thread overview: 16+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-10-11  5:26 Why guest physical addresses are not the same as the corresponding host virtual addresses in QEMU/KVM? Thanks! harry harry
2020-10-11  7:29 ` Maxim Levitsky
2020-10-11 14:11   ` harry harry
2020-10-12 16:54     ` Sean Christopherson
2020-10-13  4:30       ` harry harry
2020-10-13  4:52         ` Sean Christopherson
     [not found]           ` <CA+-xGqO4DtUs3-jH+QMPEze2GrXwtNX0z=vVUVak5HOpPKaDxQ@mail.gmail.com>
     [not found]             ` <CA+-xGqMMa-DB1SND5MRugusDafjNA9CVw-=OBK7q=CK1impmTQ@mail.gmail.com>
2020-10-13  6:43               ` Paolo Bonzini
2020-10-13 20:36                 ` harry harry
2020-10-14  8:27                   ` Paolo Bonzini
2020-10-14  8:29                   ` Maxim Levitsky
2020-10-15  3:45                     ` harry harry
2020-10-13  7:03             ` Sean Christopherson
2020-10-13 22:40               ` harry harry
2020-10-14  8:28                 ` Paolo Bonzini [this message]
2020-10-15  3:43                   ` harry harry
2020-10-13  5:00       ` harry harry

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