On 02/05/2018 08:26 PM, Mihai Donțu wrote:
On Mon, 2018-02-05 at 19:47 +0100, KarimAllah Ahmed wrote:
Guest memory can either be directly managed by the kernel (i.e. have a "struct
page") or they can simply live outside kernel control (i.e. do not have a
"struct page"). KVM mostly support these two modes, except in a few places
where the code seems to assume that guest memory must have a "struct page".
In cases where there is no 'struct page', would it be possible to get
two VM-s to share memory (in the way Xen's grant tables do)?
We are working on a page sharing mechanism and would like to know if
this use case can be accommodated.
If your code is posted somewhere, I can take a look and let you know it
can be accommodated or not.
Thank you,
This patchset introduces a new mapping function to map guest memory into host
kernel memory. Ideally I should also get rid of all guest mapping functions
that end up converting a guest address to a page, but I decided to get feedback
on this first and see if this is an acceptable API.
Most of the offending code paths that has been updated are in the nested code
base. Mostly because I stumbled upon this code while looking at the nested MSR
bitmap handling for the IBRS patches. There are also offending code paths in
SVM code, but I will do that once the interface is accepted.
KarimAllah Ahmed (12):
KVM: Introduce helper functions to map/unmap guest memory
KVM/VMX: Use the new host mapping API for apic_access_page
KVM/VMX: Use the new host mapping API for virtual_apic_page
KVM/VMX: Use the new host mapping API for pi_desc_page
KVM/VMX: Use the new host mapping API for mapping nested vmptr
KVM/VMX: Use the new host mapping API for handle_vmptrld
KVM/VMX: Use the new host mapping API for mapping L12 MSR bitmap
KVM/VMX: Use the new host mapping API for mapping nested PML
KVM/VMX: Use the new host mapping API for cmpxchg_emulated
KVM/VMX: Use the new host mapping API for synic_clear_sint_msg_pending
KVM/VMX: Use the new host mapping API for synic_deliver_msg
KVM/VMX: Remove kvm_vcpu_gpa_to_page as it is now unused
arch/x86/kvm/hyperv.c | 24 +++----
arch/x86/kvm/vmx.c | 159 ++++++++++++++++++++---------------------------
arch/x86/kvm/x86.c | 12 ++--
include/linux/kvm_host.h | 18 +++++-
virt/kvm/kvm_main.c | 62 ++++++++++++++++++
5 files changed, 161 insertions(+), 114 deletions(-)
Cc: Paolo Bonzini <pbonzini@xxxxxxxxxx>
Cc: Radim Krčmář <rkrcmar@xxxxxxxxxx>
Cc: kvm@xxxxxxxxxxxxxxx
Cc: linux-kernel@xxxxxxxxxxxxxxx
Amazon Development Center Germany GmbH
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main office: Krausenstr. 38, 10117 Berlin
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