| Message ID | d1afced8a92c01367d0aed7c6f82659c9bf79956.1625704981.git.isaku.yamahata@intel.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | TDX support | expand |
On 7/7/21 7:55 PM, isaku.yamahata@gmail.com wrote: > From: Isaku Yamahata <isaku.yamahata@intel.com> > > In TDX CPU state is also protected, thus vcpu state can't be reset by VMM. > It assumes -action reboot=shutdown instead of silently ignoring vcpu reset. > > TDX module spec version 344425-002US doesn't support vcpu reset by VMM. VM > needs to be destroyed and created again to emulate REBOOT_ACTION_RESET. > For simplicity, put its responsibility to management system like libvirt > because it's difficult for the current qemu implementation to destroy and > re-create KVM VM resources with keeping other resources. > > If management system wants reboot behavior for its users, it needs to > - set reboot_action to REBOOT_ACTION_SHUTDOWN, > - set shutdown_action to SHUTDOWN_ACTION_PAUSE optionally and, > - subscribe VM state change and on reboot, (destroy qemu if > SHUTDOWN_ACTION_PAUSE and) start new qemu. > > Signed-off-by: Isaku Yamahata <isaku.yamahata@intel.com> > --- > target/i386/kvm/tdx.c | 14 ++++++++++++++ > 1 file changed, 14 insertions(+) > > diff --git a/target/i386/kvm/tdx.c b/target/i386/kvm/tdx.c > index 1316d95209..0621317b0a 100644 > --- a/target/i386/kvm/tdx.c > +++ b/target/i386/kvm/tdx.c > @@ -25,6 +25,7 @@ > #include "qapi/qapi-types-misc-target.h" > #include "standard-headers/asm-x86/kvm_para.h" > #include "sysemu/sysemu.h" > +#include "sysemu/runstate-action.h" > #include "sysemu/kvm.h" > #include "sysemu/kvm_int.h" > #include "sysemu/tdx.h" > @@ -363,6 +364,19 @@ static void tdx_guest_init(Object *obj) > > qemu_mutex_init(&tdx->lock); > > + /* > + * TDX module spec version 344425-002US doesn't support reset of vcpu by > + * VMM. VM needs to be destroyed and created again to emulate > + * REBOOT_ACTION_RESET. For simplicity, put its responsibility to > + * management system like libvirt. > + * > + * Management system should > + * - set reboot_action to REBOOT_ACTION_SHUTDOWN > + * - set shutdown_action to SHUTDOWN_ACTION_PAUSE > + * - subscribe VM state and on reboot, destroy qemu and start new qemu > + */ > + reboot_action = REBOOT_ACTION_SHUTDOWN; > + > tdx->debug = false; > object_property_add_bool(obj, "debug", tdx_guest_get_debug, > tdx_guest_set_debug); > I think the same effect could be accomplished with modifying kvm_arch_cpu_check_are_resettable.
Hi, > In TDX CPU state is also protected, thus vcpu state can't be reset by VMM. > It assumes -action reboot=shutdown instead of silently ignoring vcpu reset. Again, better throw an error instead of silently fixing up settings. take care, Gerd
On 7/23/2021 1:54 AM, Connor Kuehl wrote: > On 7/7/21 7:55 PM, isaku.yamahata@gmail.com wrote: >> From: Isaku Yamahata <isaku.yamahata@intel.com> >> >> In TDX CPU state is also protected, thus vcpu state can't be reset by >> VMM. >> It assumes -action reboot=shutdown instead of silently ignoring vcpu >> reset. >> >> TDX module spec version 344425-002US doesn't support vcpu reset by >> VMM. VM >> needs to be destroyed and created again to emulate REBOOT_ACTION_RESET. >> For simplicity, put its responsibility to management system like libvirt >> because it's difficult for the current qemu implementation to destroy and >> re-create KVM VM resources with keeping other resources. >> >> If management system wants reboot behavior for its users, it needs to >> - set reboot_action to REBOOT_ACTION_SHUTDOWN, >> - set shutdown_action to SHUTDOWN_ACTION_PAUSE optionally and, >> - subscribe VM state change and on reboot, (destroy qemu if >> SHUTDOWN_ACTION_PAUSE and) start new qemu. >> >> Signed-off-by: Isaku Yamahata <isaku.yamahata@intel.com> >> --- >> target/i386/kvm/tdx.c | 14 ++++++++++++++ >> 1 file changed, 14 insertions(+) >> >> diff --git a/target/i386/kvm/tdx.c b/target/i386/kvm/tdx.c >> index 1316d95209..0621317b0a 100644 >> --- a/target/i386/kvm/tdx.c >> +++ b/target/i386/kvm/tdx.c >> @@ -25,6 +25,7 @@ >> #include "qapi/qapi-types-misc-target.h" >> #include "standard-headers/asm-x86/kvm_para.h" >> #include "sysemu/sysemu.h" >> +#include "sysemu/runstate-action.h" >> #include "sysemu/kvm.h" >> #include "sysemu/kvm_int.h" >> #include "sysemu/tdx.h" >> @@ -363,6 +364,19 @@ static void tdx_guest_init(Object *obj) >> qemu_mutex_init(&tdx->lock); >> + /* >> + * TDX module spec version 344425-002US doesn't support reset of >> vcpu by >> + * VMM. VM needs to be destroyed and created again to emulate >> + * REBOOT_ACTION_RESET. For simplicity, put its responsibility to >> + * management system like libvirt. >> + * >> + * Management system should >> + * - set reboot_action to REBOOT_ACTION_SHUTDOWN >> + * - set shutdown_action to SHUTDOWN_ACTION_PAUSE >> + * - subscribe VM state and on reboot, destroy qemu and start >> new qemu >> + */ >> + reboot_action = REBOOT_ACTION_SHUTDOWN; >> + >> tdx->debug = false; >> object_property_add_bool(obj, "debug", tdx_guest_get_debug, >> tdx_guest_set_debug); >> > > I think the same effect could be accomplished with modifying > kvm_arch_cpu_check_are_resettable. > Yes. Thanks for pointing it out. We will take this approach.
diff --git a/target/i386/kvm/tdx.c b/target/i386/kvm/tdx.c index 1316d95209..0621317b0a 100644 --- a/target/i386/kvm/tdx.c +++ b/target/i386/kvm/tdx.c @@ -25,6 +25,7 @@ #include "qapi/qapi-types-misc-target.h" #include "standard-headers/asm-x86/kvm_para.h" #include "sysemu/sysemu.h" +#include "sysemu/runstate-action.h" #include "sysemu/kvm.h" #include "sysemu/kvm_int.h" #include "sysemu/tdx.h" @@ -363,6 +364,19 @@ static void tdx_guest_init(Object *obj) qemu_mutex_init(&tdx->lock); + /* + * TDX module spec version 344425-002US doesn't support reset of vcpu by + * VMM. VM needs to be destroyed and created again to emulate + * REBOOT_ACTION_RESET. For simplicity, put its responsibility to + * management system like libvirt. + * + * Management system should + * - set reboot_action to REBOOT_ACTION_SHUTDOWN + * - set shutdown_action to SHUTDOWN_ACTION_PAUSE + * - subscribe VM state and on reboot, destroy qemu and start new qemu + */ + reboot_action = REBOOT_ACTION_SHUTDOWN; + tdx->debug = false; object_property_add_bool(obj, "debug", tdx_guest_get_debug, tdx_guest_set_debug);