linux-kernel - Re: [PATCH 01/14] KVM: monolithic: x86: remove kvm.ko

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:   Mon, 14 Oct 2019 18:31:44 -0700
From:   Sean Christopherson <sean.j.christopherson@...el.com>
To:     Andrea Arcangeli <aarcange@...hat.com>
Cc:     kvm@...r.kernel.org, linux-kernel@...r.kernel.org,
        Paolo Bonzini <pbonzini@...hat.com>,
        Vitaly Kuznetsov <vkuznets@...hat.com>
Subject: Re: [PATCH 01/14] KVM: monolithic: x86: remove kvm.ko

On Sat, Sep 28, 2019 at 01:23:10PM -0400, Andrea Arcangeli wrote:
> This is the first commit of a patch series that aims to replace the
> modular kvm.ko kernel module with a monolithic kvm-intel/kvm-amd
> model. This change has the only possible cons of wasting some disk
> space in /lib/modules/. The pros are that it saves CPUS and some minor
> RAM which are more scarse resources than disk space.
> 
> The pointer to function virtual template model cannot provide any
> runtime benefit because kvm-intel and kvm-amd can't be loaded at the
> same time.
> 
> This removes kvm.ko and it links and duplicates all kvm.ko objects to
> both kvm-amd and kvm-intel.

The KVM config option should be changed to a bool and its help text
updated.  Maybe something similar to the help for VIRTUALIZATION to make
it clear that enabling KVM on its own does nothing.

> 
> Signed-off-by: Andrea Arcangeli <aarcange@...hat.com>
> ---
>  arch/x86/kvm/Makefile | 5 ++---
>  1 file changed, 2 insertions(+), 3 deletions(-)
> 
> diff --git a/arch/x86/kvm/Makefile b/arch/x86/kvm/Makefile
> index 31ecf7a76d5a..68b81f381369 100644
> --- a/arch/x86/kvm/Makefile
> +++ b/arch/x86/kvm/Makefile
> @@ -12,9 +12,8 @@ kvm-y			+= x86.o mmu.o emulate.o i8259.o irq.o lapic.o \
>  			   i8254.o ioapic.o irq_comm.o cpuid.o pmu.o mtrr.o \
>  			   hyperv.o page_track.o debugfs.o
>  
> -kvm-intel-y		+= vmx/vmx.o vmx/vmenter.o vmx/pmu_intel.o vmx/vmcs12.o vmx/evmcs.o vmx/nested.o
> -kvm-amd-y		+= svm.o pmu_amd.o
> +kvm-intel-y		+= vmx/vmx.o vmx/vmenter.o vmx/pmu_intel.o vmx/vmcs12.o vmx/evmcs.o vmx/nested.o $(kvm-y)
> +kvm-amd-y		+= svm.o pmu_amd.o $(kvm-y)
>  
> -obj-$(CONFIG_KVM)	+= kvm.o
>  obj-$(CONFIG_KVM_INTEL)	+= kvm-intel.o
>  obj-$(CONFIG_KVM_AMD)	+= kvm-amd.o