3 ms·

interesting link ... from 2010 http://xen.1045712.n5.nabble.com/x2APIC-emulation-for-HVM-guest-td3288786.html http://xen.1045712.n5.nabble.com/x2APIC-emulation-

• mzs 12y ago
  good find: @@ -2189,6 +2190,11 @@ *msr_content = vcpu_vlapic(v)->hw.apic_base_msr; break; + case MSR_IA32_APICBASE_MSR ... MSR_IA32_APICBASE_MSR + 0x3ff: + if ( hvm_x2apic_msr_read(v, msr, msr_content) ) + goto gp_fault; + break; + case MSR_IA32_CR_PAT: *msr_content = v->arch.hvm_vcpu.pat_cr; break; @@ -2296,6 +2302,11 @@ vlapic_msr_set(vcpu_vlapic(v), msr_content); break; + case MSR_IA32_APICBASE_MSR ... MSR_IA32_APICBASE_MSR + 0x3ff: + if ( hvm_x2apic_msr_write(v, msr, msr_content) ) + goto gp_fault; + break; + case MSR_IA32_CR_PAT: if ( !pat_msr_set(&v->arch.hvm_vcpu.pat_cr, msr_content) ) goto gp_fault;
  • diydsp 12y ago
    What is the "..." operator? I have never seen that before. I can't find any references to it. Is that a macro specific to this project? [I checked the post above, but it doesn't match this source code exactly (and doesn't have ... as an operator).]
    • _delirium 12y ago
      It's a GNU extension that lets you define ranges in switch statements' cases: https://gcc.gnu.org/onlinedocs/gcc/Case-Ranges.html https://gcc.gnu.org/onlinedocs/gcc/Case-Ranges.html
  • walterbell 12y ago
    Is this from the Intel Xen+KVM team, crediting the patch to a member of the RedHat KVM team? Since KVM isn't vulnerable to this cross-domain issue, it may be useful to compare with the equivalent code in KVM and/or Linux.