From: David Woodhouse <d...@amazon.co.uk>
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 <d...@amazon.co.uk>
---
hw/i386/kvm/xen_evtchn.c | 121 ++++++++++++++++++++++++++++++++++++++
hw/i386/kvm/xen_evtchn.h | 2 +
target/i386/kvm/xen-emu.c | 12 ++++
3 files changed, 135 insertions(+)
diff --git a/hw/i386/kvm/xen_evtchn.c b/hw/i386/kvm/xen_evtchn.c
index 0f1abfb760..f732821d5b 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
/*
@@ -252,3 +288,88 @@ 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 6f3f8ae834..a95063434e 100644
--- a/target/i386/kvm/xen-emu.c
+++ b/target/i386/kvm/xen-emu.c
@@ -787,6 +787,18 @@ 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;
}
--
2.35.3
