kvm: x86: Dynamically allocate guest_fpu

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Previously, the guest_fpu field was embedded in the kvm_vcpu_arch
struct. Unfortunately, the field is quite large, (e.g., 4352 bytes on my
current setup). This bloats the kvm_vcpu_arch struct for x86 into an
order 3 memory allocation, which can become a problem on overcommitted
machines. Thus, this patch moves the fpu state outside of the
kvm_vcpu_arch struct.

With this patch applied, the kvm_vcpu_arch struct is reduced to 15168
bytes for vmx on my setup when building the kernel with kvmconfig.

Suggested-by: Dave Hansen <dave.hansen@intel.com>
Signed-off-by: Marc Orr <marcorr@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

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Marc Orr 2018-11-06 14:53:56 -08:00 • committed by Paolo Bonzini

parent 240c35a378

commit b666a4b697

4 changed files with 60 additions and 14 deletions

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3

arch/x86/include/asm/kvm_host.h

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10

arch/x86/kvm/svm.c

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10

arch/x86/kvm/vmx/vmx.c

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51

arch/x86/kvm/x86.c

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