From 83eb5811342b4e48544ab79dd92a0bb1a2a2cbfb Mon Sep 17 00:00:00 2001 From: David Woodhouse Date: Tue, 13 Dec 2022 13:57:44 +0000 Subject: [PATCH] hw/xen: Implement EVTCHNOP_close It calls an internal close_port() helper which will also be used from EVTCHNOP_reset and will actually do the work to disconnect/unbind a port once any of that is actually implemented in the first place. That in turn calls a free_port() internal function which will be in error paths after allocation. Signed-off-by: David Woodhouse Reviewed-by: Paul Durrant --- hw/i386/kvm/xen_evtchn.c | 123 ++++++++++++++++++++++++++++++++++++++++++++++ hw/i386/kvm/xen_evtchn.h | 2 + target/i386/kvm/xen-emu.c | 12 +++++ 3 files changed, 137 insertions(+) diff --git a/hw/i386/kvm/xen_evtchn.c b/hw/i386/kvm/xen_evtchn.c index 8bed33890f..c57d36b492 100644 --- a/hw/i386/kvm/xen_evtchn.c +++ b/hw/i386/kvm/xen_evtchn.c @@ -21,6 +21,7 @@ #include "hw/sysbus.h" #include "hw/xen/xen.h" + #include "xen_evtchn.h" #include "xen_overlay.h" @@ -40,6 +41,41 @@ typedef struct XenEvtchnPort { uint16_t type_val; /* pirq# / virq# / remote port according to type */ } XenEvtchnPort; +/* 32-bit compatibility definitions, also used natively in 32-bit build */ +struct compat_arch_vcpu_info { + unsigned int cr2; + unsigned int pad[5]; +}; + +struct compat_vcpu_info { + uint8_t evtchn_upcall_pending; + uint8_t evtchn_upcall_mask; + uint16_t pad; + uint32_t evtchn_pending_sel; + struct compat_arch_vcpu_info arch; + struct vcpu_time_info time; +}; /* 64 bytes (x86) */ + +struct compat_arch_shared_info { + unsigned int max_pfn; + unsigned int pfn_to_mfn_frame_list_list; + unsigned int nmi_reason; + unsigned int p2m_cr3; + unsigned int p2m_vaddr; + unsigned int p2m_generation; + uint32_t wc_sec_hi; +}; + +struct compat_shared_info { + struct compat_vcpu_info vcpu_info[XEN_LEGACY_MAX_VCPUS]; + uint32_t evtchn_pending[32]; + uint32_t evtchn_mask[32]; + uint32_t wc_version; /* Version counter: see vcpu_time_info_t. */ + uint32_t wc_sec; + uint32_t wc_nsec; + struct compat_arch_shared_info arch; +}; + #define COMPAT_EVTCHN_2L_NR_CHANNELS 1024 /* @@ -257,3 +293,90 @@ int xen_evtchn_status_op(struct evtchn_status *status) qemu_mutex_unlock(&s->port_lock); return 0; } + +static int clear_port_pending(XenEvtchnState *s, evtchn_port_t port) +{ + void *p = xen_overlay_get_shinfo_ptr(); + + if (!p) { + return -ENOTSUP; + } + + if (xen_is_long_mode()) { + struct shared_info *shinfo = p; + const int bits_per_word = BITS_PER_BYTE * sizeof(shinfo->evtchn_pending[0]); + typeof(shinfo->evtchn_pending[0]) mask; + int idx = port / bits_per_word; + int offset = port % bits_per_word; + + mask = 1UL << offset; + + qatomic_fetch_and(&shinfo->evtchn_pending[idx], ~mask); + } else { + struct compat_shared_info *shinfo = p; + const int bits_per_word = BITS_PER_BYTE * sizeof(shinfo->evtchn_pending[0]); + typeof(shinfo->evtchn_pending[0]) mask; + int idx = port / bits_per_word; + int offset = port % bits_per_word; + + mask = 1UL << offset; + + qatomic_fetch_and(&shinfo->evtchn_pending[idx], ~mask); + } + return 0; +} + +static void free_port(XenEvtchnState *s, evtchn_port_t port) +{ + s->port_table[port].type = EVTCHNSTAT_closed; + s->port_table[port].type_val = 0; + s->port_table[port].vcpu = 0; + + if (s->nr_ports == port + 1) { + do { + s->nr_ports--; + } while (s->nr_ports && + s->port_table[s->nr_ports - 1].type == EVTCHNSTAT_closed); + } + + /* Clear pending event to avoid unexpected behavior on re-bind. */ + clear_port_pending(s, port); +} + +static int close_port(XenEvtchnState *s, evtchn_port_t port) +{ + XenEvtchnPort *p = &s->port_table[port]; + + switch (p->type) { + case EVTCHNSTAT_closed: + return -ENOENT; + + default: + break; + } + + free_port(s, port); + return 0; +} + +int xen_evtchn_close_op(struct evtchn_close *close) +{ + XenEvtchnState *s = xen_evtchn_singleton; + int ret; + + if (!s) { + return -ENOTSUP; + } + + if (!valid_port(close->port)) { + return -EINVAL; + } + + qemu_mutex_lock(&s->port_lock); + + ret = close_port(s, close->port); + + qemu_mutex_unlock(&s->port_lock); + + return ret; +} diff --git a/hw/i386/kvm/xen_evtchn.h b/hw/i386/kvm/xen_evtchn.h index 76467636ee..cb3924941a 100644 --- a/hw/i386/kvm/xen_evtchn.h +++ b/hw/i386/kvm/xen_evtchn.h @@ -16,6 +16,8 @@ void xen_evtchn_create(void); int xen_evtchn_set_callback_param(uint64_t param); struct evtchn_status; +struct evtchn_close; int xen_evtchn_status_op(struct evtchn_status *status); +int xen_evtchn_close_op(struct evtchn_close *close); #endif /* QEMU_XEN_EVTCHN_H */ diff --git a/target/i386/kvm/xen-emu.c b/target/i386/kvm/xen-emu.c index 45fac5ea03..fab7d6b6a9 100644 --- a/target/i386/kvm/xen-emu.c +++ b/target/i386/kvm/xen-emu.c @@ -805,6 +805,18 @@ static bool kvm_xen_hcall_evtchn_op(struct kvm_xen_exit *exit, X86CPU *cpu, } break; } + case EVTCHNOP_close: { + struct evtchn_close close; + + qemu_build_assert(sizeof(close) == 4); + if (kvm_copy_from_gva(cs, arg, &close, sizeof(close))) { + err = -EFAULT; + break; + } + + err = xen_evtchn_close_op(&close); + break; + } default: return false; } -- 2.11.0