lkml.org 
[lkml]   [2009]   [Jul]   [29]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    /
    Date
    From
    SubjectRe: [PATCH 08/12] kvm/svm: cache nested intercepts
    On 07/29/2009 03:56 PM, Joerg Roedel wrote:
    > Signed-off-by: Joerg Roedel<joerg.roedel@amd.com>
    > ---
    > arch/x86/kvm/svm.c | 30 +++++++++++++++++++++++-------
    > 1 files changed, 23 insertions(+), 7 deletions(-)
    >
    > diff --git a/arch/x86/kvm/svm.c b/arch/x86/kvm/svm.c
    > index 31467b1..9192c9a 100644
    > --- a/arch/x86/kvm/svm.c
    > +++ b/arch/x86/kvm/svm.c
    > @@ -86,6 +86,15 @@ struct nested_state {
    >
    > /* gpa pointers to the real vectors */
    > u64 vmcb_msrpm;
    > +
    > + /* cache for intercepts of the guest */
    > + u16 intercept_cr_read;
    > + u16 intercept_cr_write;
    > + u16 intercept_dr_read;
    > + u16 intercept_dr_write;
    > + u32 intercept_exceptions;
    > + u64 intercept;
    > +
    > };
    >
    > struct vcpu_svm {
    > @@ -1459,7 +1468,6 @@ static int nested_svm_exit_handled_real(struct vcpu_svm *svm,
    > void *arg2,
    > void *opaque)
    > {
    > - struct vmcb *nested_vmcb = (struct vmcb *)arg1;
    > bool kvm_overrides = *(bool *)opaque;
    > u32 exit_code = svm->vmcb->control.exit_code;
    >
    > @@ -1486,38 +1494,38 @@ static int nested_svm_exit_handled_real(struct vcpu_svm *svm,
    > switch (exit_code) {
    > case SVM_EXIT_READ_CR0 ... SVM_EXIT_READ_CR8: {
    > u32 cr_bits = 1<< (exit_code - SVM_EXIT_READ_CR0);
    > - if (nested_vmcb->control.intercept_cr_read& cr_bits)
    > + if (svm->nested.intercept_cr_read& cr_bits)
    > return 1;
    > break;
    > }
    > case SVM_EXIT_WRITE_CR0 ... SVM_EXIT_WRITE_CR8: {
    > u32 cr_bits = 1<< (exit_code - SVM_EXIT_WRITE_CR0);
    > - if (nested_vmcb->control.intercept_cr_write& cr_bits)
    > + if (svm->nested.intercept_cr_write& cr_bits)
    > return 1;
    > break;
    > }
    > case SVM_EXIT_READ_DR0 ... SVM_EXIT_READ_DR7: {
    > u32 dr_bits = 1<< (exit_code - SVM_EXIT_READ_DR0);
    > - if (nested_vmcb->control.intercept_dr_read& dr_bits)
    > + if (svm->nested.intercept_dr_read& dr_bits)
    > return 1;
    > break;
    > }
    > case SVM_EXIT_WRITE_DR0 ... SVM_EXIT_WRITE_DR7: {
    > u32 dr_bits = 1<< (exit_code - SVM_EXIT_WRITE_DR0);
    > - if (nested_vmcb->control.intercept_dr_write& dr_bits)
    > + if (svm->nested.intercept_dr_write& dr_bits)
    > return 1;
    > break;
    > }
    > case SVM_EXIT_EXCP_BASE ... SVM_EXIT_EXCP_BASE + 0x1f: {
    > u32 excp_bits = 1<< (exit_code - SVM_EXIT_EXCP_BASE);
    > - if (nested_vmcb->control.intercept_exceptions& excp_bits)
    > + if (svm->nested.intercept_exceptions& excp_bits)
    > return 1;
    > break;
    > }
    > default: {
    > u64 exit_bits = 1ULL<< (exit_code - SVM_EXIT_INTR);
    > nsvm_printk("exit code: 0x%x\n", exit_code);
    > - if (nested_vmcb->control.intercept& exit_bits)
    > + if (svm->nested.intercept& exit_bits)
    > return 1;
    > }
    > }
    > @@ -1808,6 +1816,14 @@ static int nested_svm_vmrun(struct vcpu_svm *svm, void *arg1,
    >
    > svm->nested.vmcb_msrpm = nested_vmcb->control.msrpm_base_pa;
    >
    > + /* cache intercepts */
    > + svm->nested.intercept_cr_read = nested_vmcb->control.intercept_cr_read;
    > + svm->nested.intercept_cr_write = nested_vmcb->control.intercept_cr_write;
    > + svm->nested.intercept_dr_read = nested_vmcb->control.intercept_dr_read;
    > + svm->nested.intercept_dr_write = nested_vmcb->control.intercept_dr_write;
    > + svm->nested.intercept_exceptions = nested_vmcb->control.intercept_exceptions;
    > + svm->nested.intercept = nested_vmcb->control.intercept;
    > +
    > force_new_asid(&svm->vcpu);
    > svm->vmcb->control.exit_int_info = nested_vmcb->control.exit_int_info;
    > svm->vmcb->control.exit_int_info_err = nested_vmcb->control.exit_int_info_err;
    >

    I don't see the benefit of this patch. Accessing the cache is just as
    expensive as accessing the real vmcb.

    --
    error compiling committee.c: too many arguments to function



    \
     
     \ /
      Last update: 2009-07-29 15:11    [W:0.027 / U:122.900 seconds]
    ©2003-2016 Jasper Spaans. hosted at Digital OceanAdvertise on this site