[PATCH v6 09/11] x86/domctl: add XEN_DOMCTL_vmtrace_op

From: "Michał Leszczyński" <michal.leszczynski@cert.pl>
To: xen-devel@lists.xenproject.org
Cc: "Julien Grall" <julien@xen.org>,
	"Stefano Stabellini" <sstabellini@kernel.org>,
	luwei.kang@intel.com, "Wei Liu" <wl@xen.org>,
	"Andrew Cooper" <andrew.cooper3@citrix.com>,
	"Michal Leszczynski" <michal.leszczynski@cert.pl>,
	"Ian Jackson" <ian.jackson@eu.citrix.com>,
	"George Dunlap" <george.dunlap@citrix.com>,
	"Jan Beulich" <jbeulich@suse.com>,
	tamas.lengyel@intel.com, "Roger Pau Monné" <roger.pau@citrix.com>
Subject: [PATCH v6 09/11] x86/domctl: add XEN_DOMCTL_vmtrace_op
Date: Tue,  7 Jul 2020 21:39:48 +0200	[thread overview]
Message-ID: <a9899858dba4a7e22a0256cff734399bff348adb.1594150543.git.michal.leszczynski@cert.pl> (raw)
In-Reply-To: <cover.1594150543.git.michal.leszczynski@cert.pl>
In-Reply-To: <cover.1594150543.git.michal.leszczynski@cert.pl>

From: Michal Leszczynski <michal.leszczynski@cert.pl>

Implement domctl to manage the runtime state of
processor trace feature.

Signed-off-by: Michal Leszczynski <michal.leszczynski@cert.pl>
---
 xen/arch/x86/domctl.c       | 50 +++++++++++++++++++++++++++++++++++++
 xen/include/public/domctl.h | 28 +++++++++++++++++++++
 2 files changed, 78 insertions(+)

diff --git a/xen/arch/x86/domctl.c b/xen/arch/x86/domctl.c
index 6f2c69788d..6132499db4 100644
--- a/xen/arch/x86/domctl.c
+++ b/xen/arch/x86/domctl.c
@@ -322,6 +322,50 @@ void arch_get_domain_info(const struct domain *d,
     info->arch_config.emulation_flags = d->arch.emulation_flags;
 }
 
+static int do_vmtrace_op(struct domain *d, struct xen_domctl_vmtrace_op *op,
+                         XEN_GUEST_HANDLE_PARAM(xen_domctl_t) u_domctl)
+{
+    int rc;
+    struct vcpu *v;
+
+    if ( op->pad1 || op->pad2 )
+        return -EINVAL;
+
+    if ( !vmtrace_supported )
+        return -EOPNOTSUPP;
+
+    if ( !is_hvm_domain(d) )
+        return -EOPNOTSUPP;
+
+    if ( op->vcpu >= d->max_vcpus )
+        return -EINVAL;
+
+    v = domain_vcpu(d, op->vcpu);
+    rc = 0;
+
+    switch ( op->cmd )
+    {
+    case XEN_DOMCTL_vmtrace_pt_enable:
+    case XEN_DOMCTL_vmtrace_pt_disable:
+        vcpu_pause(v);
+        rc = vmtrace_control_pt(v, op->cmd == XEN_DOMCTL_vmtrace_pt_enable);
+        vcpu_unpause(v);
+        break;
+
+    case XEN_DOMCTL_vmtrace_pt_get_offset:
+        rc = vmtrace_get_pt_offset(v, &op->offset, &op->size);
+
+        if ( !rc && d->is_dying )
+            rc = ENODATA;
+        break;
+
+    default:
+        rc = -EOPNOTSUPP;
+    }
+
+    return rc;
+}
+
 #define MAX_IOPORTS 0x10000
 
 long arch_do_domctl(
@@ -337,6 +381,12 @@ long arch_do_domctl(
     switch ( domctl->cmd )
     {
 
+    case XEN_DOMCTL_vmtrace_op:
+        ret = do_vmtrace_op(d, &domctl->u.vmtrace_op, u_domctl);
+        if ( !ret )
+            copyback = true;
+        break;
+
     case XEN_DOMCTL_shadow_op:
         ret = paging_domctl(d, &domctl->u.shadow_op, u_domctl, 0);
         if ( ret == -ERESTART )
diff --git a/xen/include/public/domctl.h b/xen/include/public/domctl.h
index 7681675a94..73c7ccbd16 100644
--- a/xen/include/public/domctl.h
+++ b/xen/include/public/domctl.h
@@ -1136,6 +1136,30 @@ struct xen_domctl_vuart_op {
                                  */
 };
 
+/* XEN_DOMCTL_vmtrace_op: Perform VM tracing related operation */
+#if defined(__XEN__) || defined(__XEN_TOOLS__)
+
+struct xen_domctl_vmtrace_op {
+    /* IN variable */
+    uint32_t cmd;
+/* Enable/disable external vmtrace for given domain */
+#define XEN_DOMCTL_vmtrace_pt_enable      1
+#define XEN_DOMCTL_vmtrace_pt_disable     2
+#define XEN_DOMCTL_vmtrace_pt_get_offset  3
+    domid_t domain;
+    uint16_t pad1;
+    uint32_t vcpu;
+    uint16_t pad2;
+
+    /* OUT variable */
+    uint64_aligned_t size;
+    uint64_aligned_t offset;
+};
+typedef struct xen_domctl_vmtrace_op xen_domctl_vmtrace_op_t;
+DEFINE_XEN_GUEST_HANDLE(xen_domctl_vmtrace_op_t);
+
+#endif /* defined(__XEN__) || defined(__XEN_TOOLS__) */
+
 struct xen_domctl {
     uint32_t cmd;
 #define XEN_DOMCTL_createdomain                   1
@@ -1217,6 +1241,7 @@ struct xen_domctl {
 #define XEN_DOMCTL_vuart_op                      81
 #define XEN_DOMCTL_get_cpu_policy                82
 #define XEN_DOMCTL_set_cpu_policy                83
+#define XEN_DOMCTL_vmtrace_op                    84
 #define XEN_DOMCTL_gdbsx_guestmemio            1000
 #define XEN_DOMCTL_gdbsx_pausevcpu             1001
 #define XEN_DOMCTL_gdbsx_unpausevcpu           1002
@@ -1277,6 +1302,9 @@ struct xen_domctl {
         struct xen_domctl_monitor_op        monitor_op;
         struct xen_domctl_psr_alloc         psr_alloc;
         struct xen_domctl_vuart_op          vuart_op;
+#if defined(__XEN__) || defined(__XEN_TOOLS__)
+        struct xen_domctl_vmtrace_op        vmtrace_op;
+#endif
         uint8_t                             pad[128];
     } u;
 };
-- 
2.17.1


