[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] [Xen-devel] [PATCH v4 12/17] x86/hvm: split I/O completion handling from state model
The state of in-flight I/O and how its completion will be handled are logically separate and conflating the two makes the code unnecessarily confusing. Signed-off-by: Paul Durrant <paul.durrant@xxxxxxxxxx> Cc: Keir Fraser <keir@xxxxxxx> Cc: Jan Beulich <jbeulich@xxxxxxxx> Cc: Andrew Cooper <andrew.cooper3@xxxxxxxxxx> --- xen/arch/x86/hvm/hvm.c | 50 ++++++++++++++++++++++++------------- xen/arch/x86/hvm/io.c | 6 ++--- xen/arch/x86/hvm/vmx/realmode.c | 27 ++++++++++++++------ xen/include/asm-x86/hvm/vcpu.h | 16 ++++++++---- xen/include/asm-x86/hvm/vmx/vmx.h | 1 + 5 files changed, 68 insertions(+), 32 deletions(-) diff --git a/xen/arch/x86/hvm/hvm.c b/xen/arch/x86/hvm/hvm.c index 3365abb..39f40ad 100644 --- a/xen/arch/x86/hvm/hvm.c +++ b/xen/arch/x86/hvm/hvm.c @@ -59,6 +59,7 @@ #include <asm/hvm/trace.h> #include <asm/hvm/nestedhvm.h> #include <asm/hvm/event.h> +#include <asm/hvm/vmx/vmx.h> #include <asm/mtrr.h> #include <asm/apic.h> #include <public/sched.h> @@ -428,26 +429,12 @@ static void hvm_io_assist(ioreq_t *p) vio->io_state = HVMIO_completed; vio->io_data = p->data; break; - case HVMIO_handle_mmio_awaiting_completion: - vio->io_state = HVMIO_completed; - vio->io_data = p->data; - (void)handle_mmio(); - break; - case HVMIO_handle_pio_awaiting_completion: - if ( vio->io_size == 4 ) /* Needs zero extension. */ - guest_cpu_user_regs()->rax = (uint32_t)p->data; - else - memcpy(&guest_cpu_user_regs()->rax, &p->data, vio->io_size); - break; default: break; } - if ( p->state == STATE_IOREQ_NONE ) - { - msix_write_completion(curr); - vcpu_end_shutdown_deferral(curr); - } + msix_write_completion(curr); + vcpu_end_shutdown_deferral(curr); } static bool_t hvm_wait_for_io(struct hvm_ioreq_vcpu *sv, ioreq_t *p) @@ -482,6 +469,7 @@ void hvm_do_resume(struct vcpu *v) struct hvm_vcpu_io *vio = &v->arch.hvm_vcpu.hvm_io; struct domain *d = v->domain; struct hvm_ioreq_server *s; + enum hvm_io_completion io_completion; check_wakeup_from_wait(); @@ -508,8 +496,36 @@ void hvm_do_resume(struct vcpu *v) } } - if ( vio->mmio_retry ) + io_completion = vio->io_completion; + vio->io_completion = HVMIO_no_completion; + + switch ( io_completion ) + { + case HVMIO_no_completion: + break; + case HVMIO_mmio_completion: (void)handle_mmio(); + break; + case HVMIO_pio_completion: + if ( vio->io_size == 4 ) /* Needs zero extension. */ + guest_cpu_user_regs()->rax = (uint32_t)vio->io_data; + else + memcpy(&guest_cpu_user_regs()->rax, &vio->io_data, vio->io_size); + vio->io_state = HVMIO_none; + break; + case HVMIO_realmode_completion: + { + struct hvm_emulate_ctxt ctxt; + + hvm_emulate_prepare(&ctxt, guest_cpu_user_regs()); + vmx_realmode_emulate_one(&ctxt); + hvm_emulate_writeback(&ctxt); + + break; + } + default: + BUG(); + } /* Inject pending hw/sw trap */ if ( v->arch.hvm_vcpu.inject_trap.vector != -1 ) diff --git a/xen/arch/x86/hvm/io.c b/xen/arch/x86/hvm/io.c index 61df6dd..27150e9 100644 --- a/xen/arch/x86/hvm/io.c +++ b/xen/arch/x86/hvm/io.c @@ -92,8 +92,8 @@ int handle_mmio(void) if ( rc != X86EMUL_RETRY ) vio->io_state = HVMIO_none; - if ( vio->io_state == HVMIO_awaiting_completion ) - vio->io_state = HVMIO_handle_mmio_awaiting_completion; + if ( vio->io_state == HVMIO_awaiting_completion || vio->mmio_retry ) + vio->io_completion = HVMIO_mmio_completion; else vio->mmio_access = (struct npfec){}; @@ -158,7 +158,7 @@ int handle_pio(uint16_t port, unsigned int size, int dir) return 0; /* Completion in hvm_io_assist() with no re-emulation required. */ ASSERT(dir == IOREQ_READ); - vio->io_state = HVMIO_handle_pio_awaiting_completion; + vio->io_completion = HVMIO_pio_completion; break; default: gdprintk(XENLOG_ERR, "Weird HVM ioemulation status %d.\n", rc); diff --git a/xen/arch/x86/hvm/vmx/realmode.c b/xen/arch/x86/hvm/vmx/realmode.c index fe8b4a0..76ff9a5 100644 --- a/xen/arch/x86/hvm/vmx/realmode.c +++ b/xen/arch/x86/hvm/vmx/realmode.c @@ -101,15 +101,19 @@ static void realmode_deliver_exception( } } -static void realmode_emulate_one(struct hvm_emulate_ctxt *hvmemul_ctxt) +void vmx_realmode_emulate_one(struct hvm_emulate_ctxt *hvmemul_ctxt) { struct vcpu *curr = current; + struct hvm_vcpu_io *vio = &curr->arch.hvm_vcpu.hvm_io; int rc; perfc_incr(realmode_emulations); rc = hvm_emulate_one(hvmemul_ctxt); + if ( vio->io_state == HVMIO_awaiting_completion || vio->mmio_retry ) + vio->io_completion = HVMIO_realmode_completion; + if ( rc == X86EMUL_UNHANDLEABLE ) { gdprintk(XENLOG_ERR, "Failed to emulate insn.\n"); @@ -177,9 +181,6 @@ void vmx_realmode(struct cpu_user_regs *regs) hvm_emulate_prepare(&hvmemul_ctxt, regs); - if ( vio->io_state == HVMIO_completed ) - realmode_emulate_one(&hvmemul_ctxt); - /* Only deliver interrupts into emulated real mode. */ if ( !(curr->arch.hvm_vcpu.guest_cr[0] & X86_CR0_PE) && (intr_info & INTR_INFO_VALID_MASK) ) @@ -190,8 +191,7 @@ void vmx_realmode(struct cpu_user_regs *regs) curr->arch.hvm_vmx.vmx_emulate = 1; while ( curr->arch.hvm_vmx.vmx_emulate && - !softirq_pending(smp_processor_id()) && - (vio->io_state == HVMIO_none) ) + !softirq_pending(smp_processor_id()) ) { /* * Check for pending interrupts only every 16 instructions, because @@ -203,7 +203,10 @@ void vmx_realmode(struct cpu_user_regs *regs) hvm_local_events_need_delivery(curr) ) break; - realmode_emulate_one(&hvmemul_ctxt); + vmx_realmode_emulate_one(&hvmemul_ctxt); + + if ( vio->io_state != HVMIO_none || vio->mmio_retry ) + break; /* Stop emulating unless our segment state is not safe */ if ( curr->arch.hvm_vmx.vmx_realmode ) @@ -245,3 +248,13 @@ void vmx_realmode(struct cpu_user_regs *regs) if ( intr_info & INTR_INFO_VALID_MASK ) __vmwrite(VM_ENTRY_INTR_INFO, intr_info); } + +/* + * Local variables: + * mode: C + * c-file-style: "BSD" + * c-basic-offset: 4 + * tab-width: 4 + * indent-tabs-mode: nil + * End: + */ diff --git a/xen/include/asm-x86/hvm/vcpu.h b/xen/include/asm-x86/hvm/vcpu.h index 97d78bd..c4d96a8 100644 --- a/xen/include/asm-x86/hvm/vcpu.h +++ b/xen/include/asm-x86/hvm/vcpu.h @@ -34,11 +34,16 @@ enum hvm_io_state { HVMIO_none = 0, HVMIO_dispatched, HVMIO_awaiting_completion, - HVMIO_handle_mmio_awaiting_completion, - HVMIO_handle_pio_awaiting_completion, HVMIO_completed }; +enum hvm_io_completion { + HVMIO_no_completion = 0, + HVMIO_mmio_completion, + HVMIO_pio_completion, + HVMIO_realmode_completion +}; + struct hvm_vcpu_asid { uint64_t generation; uint32_t asid; @@ -46,9 +51,10 @@ struct hvm_vcpu_asid { struct hvm_vcpu_io { /* I/O request in flight to device model. */ - enum hvm_io_state io_state; - unsigned long io_data; - int io_size; + enum hvm_io_state io_state; + unsigned long io_data; + int io_size; + enum hvm_io_completion io_completion; /* * HVM emulation: diff --git a/xen/include/asm-x86/hvm/vmx/vmx.h b/xen/include/asm-x86/hvm/vmx/vmx.h index 35f804a..c5f3d24 100644 --- a/xen/include/asm-x86/hvm/vmx/vmx.h +++ b/xen/include/asm-x86/hvm/vmx/vmx.h @@ -94,6 +94,7 @@ void vmx_asm_do_vmentry(void); void vmx_intr_assist(void); void noreturn vmx_do_resume(struct vcpu *); void vmx_vlapic_msr_changed(struct vcpu *v); +void vmx_realmode_emulate_one(struct hvm_emulate_ctxt *hvmemul_ctxt); void vmx_realmode(struct cpu_user_regs *regs); void vmx_update_debug_state(struct vcpu *v); void vmx_update_exception_bitmap(struct vcpu *v); -- 1.7.10.4 _______________________________________________ Xen-devel mailing list Xen-devel@xxxxxxxxxxxxx http://lists.xen.org/xen-devel
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