Re: [PATCH 00/10] KVM/X86: Handle guest memory that does not have a struct page

Raslan, KarimAllah
2018-03-01T15:24:50Z

Jim/Paolo/Radim,

Any complains about the current API? (introduced in 4/10)

I have more patches on top and I would like to ensure that this is
agreed upon at least before sending more revisions/patches.

Also 1, 2, and 3 should be a bit straight forward and does not use
this API.

Thanks.

On Wed, 2018-02-21 at 18:47 +0100, KarimAllah Ahmed wrote:
> For the most part, KVM can handle guest memory that does not have a struct
> page (i.e. not directly managed by the kernel). However, There are a few places
> in the code, specially in the nested code, that does not support that.
>
> Patch 1, 2, and 3 avoid the mapping and unmapping all together and just
> directly use kvm_guest_read and kvm_guest_write.
>
> Patch 4 introduces a new guest mapping interface that encapsulate all the
> bioler plate code that is needed to map and unmap guest memory. It also
> supports guest memory without "struct page".
>
> Patch 5, 6, 7, 8, 9, and 10 switch most of the offending code in VMX and hyperv
> to use the new guest mapping API.
>
> This patch series is the first set of fixes. Handling SVM and APIC-access page
> will be handled in a different patch series.
>
> KarimAllah Ahmed (10):
> X86/nVMX: handle_vmon: Read 4 bytes from guest memory instead of
> map->read->unmap sequence
> X86/nVMX: handle_vmptrld: Copy the VMCS12 directly from guest memory
> instead of map->copy->unmap sequence.
> X86/nVMX: Update the PML table without mapping and unmapping the page
> KVM: Introduce a new guest mapping API
> KVM/nVMX: Use kvm_vcpu_map when mapping the L1 MSR bitmap
> KVM/nVMX: Use kvm_vcpu_map when mapping the virtual APIC page
> KVM/nVMX: Use kvm_vcpu_map when mapping the posted interrupt
> descriptor table
> KVM/X86: Use kvm_vcpu_map in emulator_cmpxchg_emulated
> KVM/X86: hyperv: Use kvm_vcpu_map in synic_clear_sint_msg_pending
> KVM/X86: hyperv: Use kvm_vcpu_map in synic_deliver_msg
>
> arch/x86/kvm/hyperv.c | 28 ++++-----
> arch/x86/kvm/vmx.c | 144 +++++++++++++++--------------------------------
> arch/x86/kvm/x86.c | 13 ++---
> include/linux/kvm_host.h | 15 +++++
> virt/kvm/kvm_main.c | 50 ++++++++++++++++
> 5 files changed, 129 insertions(+), 121 deletions(-)
>
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