[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] [Xen-devel] [PATCH] x86/hvm: implement save/restore for posted interrupts
Saving and restoring a PVonHVM guest on a host which has the VMX "Posted Interrupt Processing" feature enabled will fail because the xen-platform-pci device does not receive interrupts anymore after restore. The reason is that the IRQs are not maintained in APIC_IRR, but in a separate PIR array. This info is lost during the save operation. Syncing the PIR state into IRR during save, and restoring the state later will fix 'xm save/restore' of a PVonHVM guest. Signed-off-by: Olaf Hering <olaf@xxxxxxxxx> --- Jan suggested to use the TMR flag to set 'trig' for vlapic_set_irq. We are not sure if thats the correct approach, instead of forcing trig=1. Comments are welcome. xen/arch/x86/hvm/vlapic.c | 4 ++++ xen/arch/x86/hvm/vmx/vmx.c | 14 ++++++++++++++ xen/include/asm-x86/hvm/hvm.h | 1 + xen/include/asm-x86/hvm/vlapic.h | 2 ++ 4 files changed, 21 insertions(+) diff --git a/xen/arch/x86/hvm/vlapic.c b/xen/arch/x86/hvm/vlapic.c index cd7e872..7201544 100644 --- a/xen/arch/x86/hvm/vlapic.c +++ b/xen/arch/x86/hvm/vlapic.c @@ -1179,6 +1179,8 @@ static int lapic_save_regs(struct domain *d, hvm_domain_context_t *h) for_each_vcpu ( d, v ) { + if ( hvm_funcs.sync_pir_to_irr ) + hvm_funcs.sync_pir_to_irr(v); s = vcpu_vlapic(v); if ( (rc = hvm_save_entry(LAPIC_REGS, v->vcpu_id, h, s->regs)) != 0 ) break; @@ -1230,6 +1232,8 @@ static int lapic_load_regs(struct domain *d, hvm_domain_context_t *h) if ( hvm_load_entry(LAPIC_REGS, h, s->regs) != 0 ) return -EINVAL; + if ( hvm_funcs.sync_irr_to_pir ) + hvm_funcs.sync_irr_to_pir(v); if ( hvm_funcs.process_isr ) hvm_funcs.process_isr(vlapic_find_highest_isr(s), v); diff --git a/xen/arch/x86/hvm/vmx/vmx.c b/xen/arch/x86/hvm/vmx/vmx.c index 2caa04a..85df77d 100644 --- a/xen/arch/x86/hvm/vmx/vmx.c +++ b/xen/arch/x86/hvm/vmx/vmx.c @@ -1654,6 +1654,18 @@ static void vmx_sync_pir_to_irr(struct vcpu *v) vlapic_set_vector(i, &vlapic->regs->data[APIC_IRR]); } +static void vmx_sync_irr_to_pir(struct vcpu *v) +{ + struct vlapic *vlapic = vcpu_vlapic(v); + unsigned int vector; + + for ( vector = 0; vector < NR_VECTORS; vector++ ) { + if ( vlapic_test_vector(vector, &vlapic->regs->data[APIC_IRR]) ) + vlapic_set_irq(vlapic, vector, + vlapic_test_vector(vector, &vlapic->regs->data[APIC_TMR])); + } +} + static void vmx_handle_eoi(u8 vector) { unsigned long status; @@ -1737,6 +1749,7 @@ static struct hvm_function_table __initdata vmx_function_table = { .process_isr = vmx_process_isr, .deliver_posted_intr = vmx_deliver_posted_intr, .sync_pir_to_irr = vmx_sync_pir_to_irr, + .sync_irr_to_pir = vmx_sync_irr_to_pir, .handle_eoi = vmx_handle_eoi, .nhvm_hap_walk_L1_p2m = nvmx_hap_walk_L1_p2m, .hypervisor_cpuid_leaf = vmx_hypervisor_cpuid_leaf, @@ -1783,6 +1796,7 @@ const struct hvm_function_table * __init start_vmx(void) { vmx_function_table.deliver_posted_intr = NULL; vmx_function_table.sync_pir_to_irr = NULL; + vmx_function_table.sync_irr_to_pir = NULL; } if ( cpu_has_vmx_ept diff --git a/xen/include/asm-x86/hvm/hvm.h b/xen/include/asm-x86/hvm/hvm.h index 0ebd478..c762f1e 100644 --- a/xen/include/asm-x86/hvm/hvm.h +++ b/xen/include/asm-x86/hvm/hvm.h @@ -194,6 +194,7 @@ struct hvm_function_table { void (*process_isr)(int isr, struct vcpu *v); void (*deliver_posted_intr)(struct vcpu *v, u8 vector); void (*sync_pir_to_irr)(struct vcpu *v); + void (*sync_irr_to_pir)(struct vcpu *v); void (*handle_eoi)(u8 vector); /*Walk nested p2m */ diff --git a/xen/include/asm-x86/hvm/vlapic.h b/xen/include/asm-x86/hvm/vlapic.h index 66f0aff..2a83a1e 100644 --- a/xen/include/asm-x86/hvm/vlapic.h +++ b/xen/include/asm-x86/hvm/vlapic.h @@ -58,6 +58,8 @@ #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))) #define vlapic_test_and_set_vector(vec, bitmap) \ test_and_set_bit(VEC_POS(vec), (uint32_t *)((bitmap) + REG_POS(vec))) #define vlapic_test_and_clear_vector(vec, bitmap) \ _______________________________________________ Xen-devel mailing list Xen-devel@xxxxxxxxxxxxx http://lists.xen.org/xen-devel
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