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[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] Re: [Xen-devel] [Qemu-devel] [PATCH v4 1/1] xen-hvm.c: Add support for Xen access to vmport
> -----Original Message----- > From: qemu-devel-bounces+paul.durrant=citrix.com@xxxxxxxxxx > [mailto:qemu-devel-bounces+paul.durrant=citrix.com@xxxxxxxxxx] On > Behalf Of Paul Durrant > Sent: 17 October 2014 14:36 > To: Don Slutz; qemu-devel@xxxxxxxxxx > Cc: xen-devel@xxxxxxxxxxxxxxxxxxx; Marcel Apfelbaum; Michael S. Tsirkin; > Markus Armbruster; Alexander Graf; Stefano Stabellini; Anthony Liguori; > Andreas Färber > Subject: Re: [Qemu-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. > Oh, I now realize you mean the same theoretical rather than actual limit, in which case this can be a build time check anyway. Paul > 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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