[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] Re: [Xen-devel] [PATCH for 4.5 v2] vmx, apicv: fix save/restore issue with apicv
Jan Beulich wrote on 2014-10-21: >>>> On 21.10.14 at 07:32, <yang.z.zhang@xxxxxxxxx> wrote: >> --- a/xen/arch/x86/hvm/vmx/vmx.c >> +++ b/xen/arch/x86/hvm/vmx/vmx.c >> @@ -1584,6 +1584,8 @@ static void vmx_process_isr(int isr, struct >> vcpu >> *v) { >> unsigned long status; >> u8 old; >> + unsigned int i, vector; > > I don't really see the need for two variables here - just "i" would > seem to suffice. > >> + struct vlapic *vlapic = vcpu_vlapic(v); > > const? > >> @@ -1597,6 +1599,28 @@ static void vmx_process_isr(int isr, struct >> vcpu > *v) >> status |= isr << VMX_GUEST_INTR_STATUS_SVI_OFFSET; >> __vmwrite(GUEST_INTR_STATUS, status); >> } >> + >> + /* >> + * Theoretically, only level triggered interrupts can have their >> + * corresponding bits set in the eoi exit bitmap. That is, the bits >> + * set in the eoi exit bitmap should also be set in TMR. But a periodic >> + * timer interrupt does not follow the rule: it is edge triggered, but >> + * requires its corresponding bit be set in the eoi exit bitmap. So we >> + * should not construct the eoi exit bitmap based on TMR. >> + * Here we will construct the eoi exit bitmap via (IRR | ISR). This >> + * means that EOIs to the interrupts that are set in the IRR or ISR will >> + * cause VM exits after restoring, regardless of the trigger modes. It >> + * is acceptable because the subsequent interrupts will set up the eoi >> + * bitmap correctly. >> + */ >> + for ( vector = 0x10; vector < NR_VECTORS; vector++ ) >> + if ( vlapic_test_vector(vector, &vlapic->regs->data[APIC_IRR]) || >> + vlapic_test_vector(vector, &vlapic->regs->data[APIC_ISR]) ) >> + set_bit(vector, v->arch.hvm_vmx.eoi_exit_bitmap); >> + >> + for ( i = 0; i < 4; i++ ) > > ARRAY_SIZE(v->arch.hvm_vmx.eoi_exit_bitmap) instead of 4 please, like > already done in construct_vmcs(). > >> + __vmwrite(EOI_EXIT_BITMAP(i), >> + v->arch.hvm_vmx.eoi_exit_bitmap[i]); >> + >> vmx_vmcs_exit(v); >> } >> --- a/xen/include/asm-x86/hvm/vlapic.h >> +++ b/xen/include/asm-x86/hvm/vlapic.h >> @@ -61,6 +61,8 @@ >> >> #define VEC_POS(v) ((v) % 32) >> #define REG_POS(v) (((v) / 32) * 0x10) >> +#define vlapic_test_vector(vec, bitmap) \ + test_bit(VEC_POS(vec), >> (uint32_t *)((bitmap) + REG_POS(vec))) > > Don't cast away possible const-ness here. > > But of course if there are no other needs to change the patch I could > take care of all of these while committing. It appears no other comments. Should I send out the v3 or you will help to commit it with modifications? Best regards, Yang _______________________________________________ Xen-devel mailing list Xen-devel@xxxxxxxxxxxxx http://lists.xen.org/xen-devel
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