On 06/05/21 19:35, Stamatis, Ilias wrote:
On Thu, 2021-05-06 at 13:32 +0200, Paolo Bonzini wrote:
On 06/05/21 12:32, ilstam@xxxxxxxxxxx wrote:
+ if (vmcs12->cpu_based_vm_exec_control &
CPU_BASED_USE_TSC_OFFSETTING) {
+ if (vmcs12->secondary_vm_exec_control &
SECONDARY_EXEC_TSC_SCALING) {
+ vcpu->arch.tsc_offset =
kvm_compute_02_tsc_offset(
+ vcpu->arch.l1_tsc_offset,
+ vmcs12->tsc_multiplier,
+ vmcs12->tsc_offset);
+
+ vcpu->arch.tsc_scaling_ratio =
mul_u64_u64_shr(
+ vcpu->arch.tsc_scaling_ratio,
+ vmcs12->tsc_multiplier,
+ kvm_tsc_scaling_ratio_frac_bit
s);
+ } else {
+ vcpu->arch.tsc_offset += vmcs12->tsc_offset;
+ }
The computation of vcpu->arch.tsc_offset is (not coincidentially) the
same that appears in patch 6
+ (vmcs12->cpu_based_vm_exec_control &
CPU_BASED_USE_TSC_OFFSETTING)) {
+ if (vmcs12->secondary_vm_exec_control &
SECONDARY_EXEC_TSC_SCALING) {
+ cur_offset = kvm_compute_02_tsc_offset(
+ l1_offset,
+ vmcs12->tsc_multiplier,
+ vmcs12->tsc_offset);
+ } else {
+ cur_offset = l1_offset + vmcs12->tsc_offset;
So I think you should just pass vmcs12 and the L1 offset to
kvm_compute_02_tsc_offset, and let it handle both cases (and possibly
even set vcpu->arch.tsc_scaling_ratio in the same function).
That was my thinking initially too. However, kvm_compute_02_tsc_offset
is defined in x86.c which is vmx-agnostic and hence 'struct vmcs12' is
not defined there.
Good point. Yeah, it's trading one comde duplication for another.
Right now there's already code duplication in write_l1_tsc_offset, so it
makes some sense to limit duplication _within_ the file and lose in
duplicated code across vmx/svm, but either is okay.
Paolo
