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[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] Re: [Xen-devel] [PATCH v4 1/1] xen-hvm.c: Add support for Xen access to vmport
> -----Original Message----- > From: Don Slutz [mailto:dslutz@xxxxxxxxxxx] > Sent: 17 October 2014 14:31 > To: Paul Durrant; Don Slutz; qemu-devel@xxxxxxxxxx > Cc: xen-devel@xxxxxxxxxxxxxxxxxxx; Alexander Graf; Andreas Färber; > Anthony Liguori; Marcel Apfelbaum; Markus Armbruster; Michael S. Tsirkin; > Stefano Stabellini > Subject: Re: [PATCH v4 1/1] xen-hvm.c: Add support for Xen access to > vmport > > On 10/17/14 08:34, Paul Durrant wrote: > >> -----Original Message----- > >> From: Don Slutz [mailto:dslutz@xxxxxxxxxxx] > >> Sent: 17 October 2014 13:14 > >> To: qemu-devel@xxxxxxxxxx; Paul Durrant > >> Cc: xen-devel@xxxxxxxxxxxxxxxxxxx; Alexander Graf; Andreas Färber; > >> Anthony Liguori; Don Slutz; Marcel Apfelbaum; Markus Armbruster; > Michael > >> S. Tsirkin; Stefano Stabellini > >> Subject: [PATCH v4 1/1] xen-hvm.c: Add support for Xen access to vmport > >> > >> This adds synchronisation of the 6 vcpu registers (only 32bits of > >> them) that vmport.c needs between Xen and QEMU. > >> > >> This is to avoid a 2nd and 3rd exchange between QEMU and Xen to > >> fetch and put these 6 vcpu registers used by the code in vmport.c > >> and vmmouse.c > >> > >> The registers are passed in the new shared page provided by > >> HVM_PARAM_VMPORT_IOREQ_PFN. > >> > >> Add new array to XenIOState that allows selection of current_cpu by > >> ioreq_id. > >> > >> Now pass XenIOState to handle_ioreq(). > >> > >> Add new routines regs_to_cpu(), regs_from_cpu(), and > >> handle_vmport_ioreq(). > >> > >> Signed-off-by: Don Slutz <dslutz@xxxxxxxxxxx> > >> --- > >> include/hw/xen/xen_common.h | 15 ++++++ > >> xen-hvm.c | 121 > >> ++++++++++++++++++++++++++++++++++++++++++-- > >> 2 files changed, 131 insertions(+), 5 deletions(-) > >> > >> diff --git a/include/hw/xen/xen_common.h > >> b/include/hw/xen/xen_common.h > >> index 07731b9..9542756 100644 > >> --- a/include/hw/xen/xen_common.h > >> +++ b/include/hw/xen/xen_common.h > >> @@ -164,4 +164,19 @@ void destroy_hvm_domain(bool reboot); > >> /* shutdown/destroy current domain because of an error */ > >> void xen_shutdown_fatal_error(const char *fmt, ...) GCC_FMT_ATTR(1, > 2); > >> > >> +#ifdef HVM_PARAM_VMPORT_IOREQ_PFN > >> +static inline int xen_get_vmport_ioreq_pfn(XenXC xc, domid_t dom, > >> + unsigned long > >> *vmport_ioreq_pfn) > >> +{ > >> + return xc_get_hvm_param(xc, dom, > >> HVM_PARAM_VMPORT_IOREQ_PFN, > >> + vmport_ioreq_pfn); > >> +} > >> +#else > >> +static inline int xen_get_vmport_ioreq_pfn(XenXC xc, domid_t dom, > >> + unsigned long > >> *vmport_ioreq_pfn) > >> +{ > >> + return -ENOSYS; > >> +} > >> +#endif > >> + > >> #endif /* QEMU_HW_XEN_COMMON_H */ > >> diff --git a/xen-hvm.c b/xen-hvm.c > >> index 05e522c..17b3cbd 100644 > >> --- a/xen-hvm.c > >> +++ b/xen-hvm.c > >> @@ -41,6 +41,29 @@ static MemoryRegion *framebuffer; > >> static bool xen_in_migration; > >> > >> /* Compatibility with older version */ > >> + > >> +/* This allows QEMU to build on a system that has Xen 4.5 or earlier > >> + * installed. This here (not in hw/xen/xen_common.h) because > >> xen/hvm/ioreq.h > >> + * needs to be included before this block and hw/xen/xen_common.h > >> needs to > >> + * be included before xen/hvm/ioreq.h > >> + */ > >> +#ifndef IOREQ_TYPE_VMWARE_PORT > >> +#define IOREQ_TYPE_VMWARE_PORT 3 > >> +struct vmware_ioreq { > >> + uint32_t esi; > >> + uint32_t edi; > >> + uint32_t ebx; > >> + uint32_t ecx; > >> + uint32_t edx; > >> +}; > >> +typedef struct vmware_ioreq vmware_ioreq_t; > > This struct is not really a request any more. Maybe vmware_regs_t? > > Sure. > > >> + > >> +struct shared_vmport_iopage { > >> + struct vmware_ioreq vcpu_vmport_ioreq[1]; > >> +}; > >> +typedef struct shared_vmport_iopage shared_vmport_iopage_t; > >> +#endif > >> + > >> #if __XEN_LATEST_INTERFACE_VERSION__ < 0x0003020a > >> static inline uint32_t xen_vcpu_eport(shared_iopage_t *shared_page, > int i) > >> { > >> @@ -79,8 +102,10 @@ typedef struct XenPhysmap { > >> > >> typedef struct XenIOState { > >> shared_iopage_t *shared_page; > >> + shared_vmport_iopage_t *shared_vmport_page; > >> buffered_iopage_t *buffered_io_page; > >> QEMUTimer *buffered_io_timer; > >> + CPUState **cpu_by_ioreq_id; > > This name implies the array is indexed by an id carries in the ioreq. That > doesn't seem to be the case; it's just indexed by guest vcpu id isn't it? > > Yes. How about cpu_by_vcpu_id ? Ok. > > >> /* the evtchn port for polling the notification, */ > >> evtchn_port_t *ioreq_local_port; > >> /* evtchn local port for buffered io */ > >> @@ -101,6 +126,8 @@ typedef struct XenIOState { > >> Notifier wakeup; > >> } XenIOState; > >> > >> +static void handle_ioreq(XenIOState *state, ioreq_t *req); > >> + > >> /* Xen specific function for piix pci */ > >> > >> int xen_pci_slot_get_pirq(PCIDevice *pci_dev, int irq_num) > >> @@ -610,6 +637,20 @@ static ioreq_t > >> *cpu_get_ioreq_from_shared_memory(XenIOState *state, int vcpu) > >> return req; > >> } > >> > >> +/* get the vmport ioreq packets from share mem */ > >> +static vmware_ioreq_t > *cpu_get_vmport_ioreq_from_shared_memory( > > Is this worth its own function? I can only see one use of it in > handle_vmport_ioreq below... > > Will move it in-line. I was just following > cpu_get_ioreq_from_shared_memory which also has 1 use. > > >> + XenIOState *state, int vcpu) > >> +{ > >> + vmware_ioreq_t *vmport_req; > >> + > >> + assert(state->shared_vmport_page); > >> + vmport_req = &state->shared_vmport_page- > >>> vcpu_vmport_ioreq[vcpu]; > >> + > >> + xen_rmb(); /* see IOREQ_READY /then/ read contents of ioreq */ > > I don't think that comment is applicable here, and I don't think you need > the barrier anyway. > > I was not sure either way, so went with the safe way. Will drop. > > >> + > >> + return vmport_req; > >> +} > >> + > >> /* use poll to get the port notification */ > >> /* ioreq_vec--out,the */ > >> /* retval--the number of ioreq packet */ > >> @@ -773,7 +814,50 @@ static void cpu_ioreq_move(ioreq_t *req) > >> } > >> } > >> > >> -static void handle_ioreq(ioreq_t *req) > >> +static void regs_to_cpu(XenIOState *state, vmware_ioreq_t > *vmport_req, > >> + ioreq_t *req) > >> +{ > >> + X86CPU *cpu; > >> + CPUX86State *env; > >> + > >> + current_cpu = state->cpu_by_ioreq_id[state->send_vcpu]; > >> + cpu = X86_CPU(current_cpu); > >> + env = &cpu->env; > >> + env->regs[R_EAX] = req->data; > >> + env->regs[R_EBX] = vmport_req->ebx; > >> + env->regs[R_ECX] = vmport_req->ecx; > >> + env->regs[R_EDX] = vmport_req->edx; > >> + env->regs[R_ESI] = vmport_req->esi; > >> + env->regs[R_EDI] = vmport_req->edi; > >> +} > >> + > >> +static void regs_from_cpu(XenIOState *state, vmware_ioreq_t > >> *vmport_req, > >> + ioreq_t *req) > >> +{ > >> + X86CPU *cpu = X86_CPU(current_cpu); > >> + CPUX86State *env = &cpu->env; > >> + > >> + assert(sizeof(*vmport_req) <= sizeof(*req)); > > Why? > > Since there is 1 page of ioreq_t indexed by vcpu id this checks that > the 1 page of vmport data has at least the same number of vcpu > slots. Does it? It looks like it checks that the size of the vmware_ioreq_t structure is less than or equal to the size of the ioreq_t structure to me. I see nothing checking number of array elements. Paul > This prevents a bad memory read. Looks to not be the right place > for this, will move. > > >> + > >> + vmport_req->ebx = env->regs[R_EBX]; > >> + vmport_req->ecx = env->regs[R_ECX]; > >> + vmport_req->edx = env->regs[R_EDX]; > >> + vmport_req->esi = env->regs[R_ESI]; > >> + vmport_req->edi = env->regs[R_EDI]; > >> + current_cpu = NULL; > >> +} > >> + > >> +static void handle_vmport_ioreq(XenIOState *state, ioreq_t *req) > >> +{ > >> + vmware_ioreq_t *vmport_req = > >> + cpu_get_vmport_ioreq_from_shared_memory(state, state- > >>> send_vcpu); > >> + > >> + regs_to_cpu(state, vmport_req, req); > >> + cpu_ioreq_pio(req); > >> + regs_from_cpu(state, vmport_req, req); > > state appears to be unused in this function, and you could avoid passing it > to both of them by setting current_cpu here couldn't you? > > Yes, will move state code here. > > -Don Slutz > > > Paul > > > >> +} > >> + > >> +static void handle_ioreq(XenIOState *state, ioreq_t *req) > >> { > >> if (!req->data_is_ptr && (req->dir == IOREQ_WRITE) && > >> (req->size < sizeof (target_ulong))) { > >> @@ -787,6 +871,9 @@ static void handle_ioreq(ioreq_t *req) > >> case IOREQ_TYPE_COPY: > >> cpu_ioreq_move(req); > >> break; > >> + case IOREQ_TYPE_VMWARE_PORT: > >> + handle_vmport_ioreq(state, req); > >> + break; > >> case IOREQ_TYPE_TIMEOFFSET: > >> break; > >> case IOREQ_TYPE_INVALIDATE: > >> @@ -828,7 +915,7 @@ static int handle_buffered_iopage(XenIOState > >> *state) > >> req.data |= ((uint64_t)buf_req->data) << 32; > >> } > >> > >> - handle_ioreq(&req); > >> + handle_ioreq(state, &req); > >> > >> xen_mb(); > >> state->buffered_io_page->read_pointer += qw ? 2 : 1; > >> @@ -857,14 +944,16 @@ static void cpu_handle_ioreq(void *opaque) > >> > >> handle_buffered_iopage(state); > >> if (req) { > >> - handle_ioreq(req); > >> + handle_ioreq(state, req); > >> > >> if (req->state != STATE_IOREQ_INPROCESS) { > >> fprintf(stderr, "Badness in I/O request ... not in > >> service?!: " > >> "%x, ptr: %x, port: %"PRIx64", " > >> - "data: %"PRIx64", count: %" FMT_ioreq_size ", size: %" > >> FMT_ioreq_size "\n", > >> + "data: %"PRIx64", count: %" FMT_ioreq_size > >> + ", size: %" FMT_ioreq_size > >> + ", type: %"FMT_ioreq_size"\n", > >> req->state, req->data_is_ptr, req->addr, > >> - req->data, req->count, req->size); > >> + req->data, req->count, req->size, req->type); > >> destroy_hvm_domain(false); > >> return; > >> } > >> @@ -904,6 +993,14 @@ static void xen_main_loop_prepare(XenIOState > >> *state) > >> state); > >> > >> if (evtchn_fd != -1) { > >> + CPUState *cpu_state; > >> + > >> + DPRINTF("%s: Init cpu_by_ioreq_id\n", __func__); > >> + CPU_FOREACH(cpu_state) { > >> + DPRINTF("%s: cpu_by_ioreq_id[%d]=%p\n", > >> + __func__, cpu_state->cpu_index, cpu_state); > >> + state->cpu_by_ioreq_id[cpu_state->cpu_index] = cpu_state; > >> + } > >> qemu_set_fd_handler(evtchn_fd, cpu_handle_ioreq, NULL, state); > >> } > >> } > >> @@ -1020,6 +1117,17 @@ int xen_hvm_init(ram_addr_t > >> *below_4g_mem_size, ram_addr_t *above_4g_mem_size, > >> errno, xen_xc); > >> } > >> > >> + if (!xen_get_vmport_ioreq_pfn(xen_xc, xen_domid, &ioreq_pfn)) { > >> + DPRINTF("shared vmport page at pfn %lx\n", ioreq_pfn); > >> + state->shared_vmport_page = > >> + xc_map_foreign_range(xen_xc, xen_domid, XC_PAGE_SIZE, > >> + PROT_READ|PROT_WRITE, ioreq_pfn); > >> + if (state->shared_vmport_page == NULL) { > >> + hw_error("map shared vmport IO page returned error %d > handle=" > >> + XC_INTERFACE_FMT, errno, xen_xc); > >> + } > >> + } > >> + > >> xc_get_hvm_param(xen_xc, xen_domid, > HVM_PARAM_BUFIOREQ_PFN, > >> &ioreq_pfn); > >> DPRINTF("buffered io page at pfn %lx\n", ioreq_pfn); > >> state->buffered_io_page = xc_map_foreign_range(xen_xc, > xen_domid, > >> XC_PAGE_SIZE, > >> @@ -1028,6 +1136,9 @@ int xen_hvm_init(ram_addr_t > >> *below_4g_mem_size, ram_addr_t *above_4g_mem_size, > >> hw_error("map buffered IO page returned error %d", errno); > >> } > >> > >> + /* Note: cpus is empty at this point in init */ > >> + state->cpu_by_ioreq_id = g_malloc0(max_cpus * sizeof(CPUState *)); > >> + > >> state->ioreq_local_port = g_malloc0(max_cpus * sizeof > (evtchn_port_t)); > >> > >> /* FIXME: how about if we overflow the page here? */ > >> -- > >> 1.8.4 _______________________________________________ Xen-devel mailing list Xen-devel@xxxxxxxxxxxxx http://lists.xen.org/xen-devel
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