| Message ID | 20230124025939.6480-2-jandryuk@gmail.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | tools: guest kexec fixes | expand |
On Mon, Jan 23, 2023 at 09:59:38PM -0500, Jason Andryuk wrote: > When a domain performs a kexec (soft reset), libxl__build_pre() is > called with the existing domid. Calling libxl__cpuid_legacy() on the > existing domain fails since the cpuid policy has already been set, and > the guest isn't rebuilt and doesn't kexec. > > xc: error: Failed to set d1's policy (err leaf 0xffffffff, subleaf 0xffffffff, msr 0xffffffff) (17 = File exists): Internal error > libxl: error: libxl_cpuid.c:494:libxl__cpuid_legacy: Domain 1:Failed to apply CPUID policy: File exists > libxl: error: libxl_create.c:1641:domcreate_rebuild_done: Domain 1:cannot (re-)build domain: -3 > libxl: error: libxl_xshelp.c:201:libxl__xs_read_mandatory: xenstore read failed: `/libxl/1/type': No such file or directory > libxl: warning: libxl_dom.c:49:libxl__domain_type: unable to get domain type for domid=1, assuming HVM > > During a soft_reset, skip calling libxl__cpuid_legacy() to avoid the > issue. Before the fixes commit, the libxl__cpuid_legacy() failure would s/fixes/fixed/ or maybe better just write: "before commit 34990446ca91". > have been ignored, so kexec would continue. > > Fixes: 34990446ca91 "libxl: don't ignore the return value from xc_cpuid_apply_policy" FYI, the tags format is with () around the commit title: Fixes: 34990446ca91 ("libxl: don't ignore the return value from xc_cpuid_apply_policy") I have this in my git config file to help generate those: [alias] fixes = log -1 --abbrev=12 --format=tformat:'Fixes: %h (\"%s\")' > Signed-off-by: Jason Andryuk <jandryuk@gmail.com> > --- > Probably a backport candidate since this has been broken for a while. > > v2: > Use soft_reset field in libxl__domain_build_state. - Juergen Reviewed-by: Anthony PERARD <anthony.perard@citrix.com> Thanks,
diff --git a/tools/libs/light/libxl_create.c b/tools/libs/light/libxl_create.c index 5cddc3df79..2eaffe7906 100644 --- a/tools/libs/light/libxl_create.c +++ b/tools/libs/light/libxl_create.c @@ -2210,6 +2210,8 @@ static int do_domain_soft_reset(libxl_ctx *ctx, aop_console_how); cdcs->domid_out = &domid_out; + state->soft_reset = true; + dom_path = libxl__xs_get_dompath(gc, domid); if (!dom_path) { LOGD(ERROR, domid, "failed to read domain path"); diff --git a/tools/libs/light/libxl_dom.c b/tools/libs/light/libxl_dom.c index b454f988fb..f6311eea6e 100644 --- a/tools/libs/light/libxl_dom.c +++ b/tools/libs/light/libxl_dom.c @@ -382,7 +382,7 @@ int libxl__build_pre(libxl__gc *gc, uint32_t domid, /* Construct a CPUID policy, but only for brand new domains. Domains * being migrated-in/restored have CPUID handled during the * static_data_done() callback. */ - if (!state->restore) + if (!state->restore && !state->soft_reset) rc = libxl__cpuid_legacy(ctx, domid, false, info); out: diff --git a/tools/libs/light/libxl_internal.h b/tools/libs/light/libxl_internal.h index 0dc8b8f210..ad982d691a 100644 --- a/tools/libs/light/libxl_internal.h +++ b/tools/libs/light/libxl_internal.h @@ -1411,6 +1411,7 @@ typedef struct { /* Whether this domain is being migrated/restored, or booting fresh. Only * applicable to the primary domain, not support domains (e.g. stub QEMU). */ bool restore; + bool soft_reset; } libxl__domain_build_state; _hidden void libxl__domain_build_state_init(libxl__domain_build_state *s);
When a domain performs a kexec (soft reset), libxl__build_pre() is called with the existing domid. Calling libxl__cpuid_legacy() on the existing domain fails since the cpuid policy has already been set, and the guest isn't rebuilt and doesn't kexec. xc: error: Failed to set d1's policy (err leaf 0xffffffff, subleaf 0xffffffff, msr 0xffffffff) (17 = File exists): Internal error libxl: error: libxl_cpuid.c:494:libxl__cpuid_legacy: Domain 1:Failed to apply CPUID policy: File exists libxl: error: libxl_create.c:1641:domcreate_rebuild_done: Domain 1:cannot (re-)build domain: -3 libxl: error: libxl_xshelp.c:201:libxl__xs_read_mandatory: xenstore read failed: `/libxl/1/type': No such file or directory libxl: warning: libxl_dom.c:49:libxl__domain_type: unable to get domain type for domid=1, assuming HVM During a soft_reset, skip calling libxl__cpuid_legacy() to avoid the issue. Before the fixes commit, the libxl__cpuid_legacy() failure would have been ignored, so kexec would continue. Fixes: 34990446ca91 "libxl: don't ignore the return value from xc_cpuid_apply_policy" Signed-off-by: Jason Andryuk <jandryuk@gmail.com> --- Probably a backport candidate since this has been broken for a while. v2: Use soft_reset field in libxl__domain_build_state. - Juergen --- tools/libs/light/libxl_create.c | 2 ++ tools/libs/light/libxl_dom.c | 2 +- tools/libs/light/libxl_internal.h | 1 + 3 files changed, 4 insertions(+), 1 deletion(-)