|
[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] Re: [Xen-devel] [PATCH v6] x86/hvm: Allow guest_request vm_events coming from userspace
On Thu, Aug 17, 2017 at 5:50 AM, Alexandru Isaila
<aisaila@xxxxxxxxxxxxxxx> wrote:
> In some introspection usecases, an in-guest agent needs to communicate
> with the external introspection agent. An existing mechanism is
> HVMOP_guest_request_vm_event, but this is restricted to kernel usecases
> like all other hypercalls.
>
> Introduce a mechanism whereby the introspection agent can whitelist the
> use of HVMOP_guest_request_vm_event directly from userspace.
>
> Signed-off-by: Alexandru Isaila <aisaila@xxxxxxxxxxxxxxx>
Acked-by: Tamas K Lengyel <tamas@xxxxxxxxxxxxx>
>
> ---
> Changes since V5:
> - Added the bool allow_userspace to the xc_monitor_guest_request
> function
> ---
> tools/libxc/include/xenctrl.h | 2 +-
> tools/libxc/xc_monitor.c | 3 ++-
> xen/arch/x86/hvm/hypercall.c | 5 +++++
> xen/common/monitor.c | 1 +
> xen/include/asm-x86/domain.h | 19 ++++++++++---------
> xen/include/public/domctl.h | 1 +
> 6 files changed, 20 insertions(+), 11 deletions(-)
>
> diff --git a/tools/libxc/include/xenctrl.h b/tools/libxc/include/xenctrl.h
> index bde8313..a3d0929 100644
> --- a/tools/libxc/include/xenctrl.h
> +++ b/tools/libxc/include/xenctrl.h
> @@ -2021,7 +2021,7 @@ int xc_monitor_software_breakpoint(xc_interface *xch,
> domid_t domain_id,
> int xc_monitor_descriptor_access(xc_interface *xch, domid_t domain_id,
> bool enable);
> int xc_monitor_guest_request(xc_interface *xch, domid_t domain_id,
> - bool enable, bool sync);
> + bool enable, bool sync, bool allow_userspace);
> int xc_monitor_debug_exceptions(xc_interface *xch, domid_t domain_id,
> bool enable, bool sync);
> int xc_monitor_cpuid(xc_interface *xch, domid_t domain_id, bool enable);
> diff --git a/tools/libxc/xc_monitor.c b/tools/libxc/xc_monitor.c
> index b44ce93..a677820 100644
> --- a/tools/libxc/xc_monitor.c
> +++ b/tools/libxc/xc_monitor.c
> @@ -147,7 +147,7 @@ int xc_monitor_descriptor_access(xc_interface *xch,
> domid_t domain_id,
> }
>
> int xc_monitor_guest_request(xc_interface *xch, domid_t domain_id, bool
> enable,
> - bool sync)
> + bool sync, bool allow_userspace)
> {
> DECLARE_DOMCTL;
>
> @@ -157,6 +157,7 @@ int xc_monitor_guest_request(xc_interface *xch, domid_t
> domain_id, bool enable,
> : XEN_DOMCTL_MONITOR_OP_DISABLE;
> domctl.u.monitor_op.event = XEN_DOMCTL_MONITOR_EVENT_GUEST_REQUEST;
> domctl.u.monitor_op.u.guest_request.sync = sync;
> + domctl.u.monitor_op.u.guest_request.allow_userspace = enable ?
> allow_userspace : false;
>
> return do_domctl(xch, &domctl);
> }
> diff --git a/xen/arch/x86/hvm/hypercall.c b/xen/arch/x86/hvm/hypercall.c
> index e7238ce..5742dd1 100644
> --- a/xen/arch/x86/hvm/hypercall.c
> +++ b/xen/arch/x86/hvm/hypercall.c
> @@ -155,6 +155,11 @@ int hvm_hypercall(struct cpu_user_regs *regs)
> /* Fallthrough to permission check. */
> case 4:
> case 2:
> + if ( currd->arch.monitor.guest_request_userspace_enabled &&
> + eax == __HYPERVISOR_hvm_op &&
> + (mode == 8 ? regs->rdi : regs->ebx) ==
> HVMOP_guest_request_vm_event )
> + break;
> +
> if ( unlikely(hvm_get_cpl(curr)) )
> {
> default:
> diff --git a/xen/common/monitor.c b/xen/common/monitor.c
> index 451f42f..20463e0 100644
> --- a/xen/common/monitor.c
> +++ b/xen/common/monitor.c
> @@ -75,6 +75,7 @@ int monitor_domctl(struct domain *d, struct
> xen_domctl_monitor_op *mop)
> domain_pause(d);
> d->monitor.guest_request_sync = mop->u.guest_request.sync;
> d->monitor.guest_request_enabled = requested_status;
> + d->arch.monitor.guest_request_userspace_enabled =
> mop->u.guest_request.allow_userspace;
> domain_unpause(d);
> break;
> }
> diff --git a/xen/include/asm-x86/domain.h b/xen/include/asm-x86/domain.h
> index c10522b..de02507 100644
> --- a/xen/include/asm-x86/domain.h
> +++ b/xen/include/asm-x86/domain.h
> @@ -396,15 +396,16 @@ struct arch_domain
>
> /* Arch-specific monitor options */
> struct {
> - unsigned int write_ctrlreg_enabled : 4;
> - unsigned int write_ctrlreg_sync : 4;
> - unsigned int write_ctrlreg_onchangeonly : 4;
> - unsigned int singlestep_enabled : 1;
> - unsigned int software_breakpoint_enabled : 1;
> - unsigned int debug_exception_enabled : 1;
> - unsigned int debug_exception_sync : 1;
> - unsigned int cpuid_enabled : 1;
> - unsigned int descriptor_access_enabled : 1;
> + unsigned int write_ctrlreg_enabled :
> 4;
> + unsigned int write_ctrlreg_sync :
> 4;
> + unsigned int write_ctrlreg_onchangeonly :
> 4;
> + unsigned int singlestep_enabled :
> 1;
> + unsigned int software_breakpoint_enabled :
> 1;
> + unsigned int debug_exception_enabled :
> 1;
> + unsigned int debug_exception_sync :
> 1;
> + unsigned int cpuid_enabled :
> 1;
> + unsigned int descriptor_access_enabled :
> 1;
> + unsigned int guest_request_userspace_enabled :
> 1;
> struct monitor_msr_bitmap *msr_bitmap;
> uint64_t write_ctrlreg_mask[4];
> } monitor;
> diff --git a/xen/include/public/domctl.h b/xen/include/public/domctl.h
> index ff39762..5997c52 100644
> --- a/xen/include/public/domctl.h
> +++ b/xen/include/public/domctl.h
> @@ -1124,6 +1124,7 @@ struct xen_domctl_monitor_op {
> struct {
> /* Pause vCPU until response */
> uint8_t sync;
> + uint8_t allow_userspace;
> } guest_request;
>
> struct {
> --
> 2.7.4
_______________________________________________
Xen-devel mailing list
Xen-devel@xxxxxxxxxxxxx
https://lists.xen.org/xen-devel
|
 |
Lists.xenproject.org is hosted with RackSpace, monitoring our |