From: Igor Druzhinin Date: Fri, 28 Oct 2022 13:48:50 +0000 (+0200) Subject: x86/pv-shim: correct ballooning up for compat guests X-Git-Tag: archive/raspbian/4.17.0-1+rpi1^2~33^2~89 X-Git-Url: https://dgit.raspbian.org/%22http://www.example.com/cgi/%22/%22http:/www.example.com/cgi/%22?a=commitdiff_plain;h=a0bfdd201ea12aa5679bb8944d63a4e0d3c23160;p=xen.git x86/pv-shim: correct ballooning up for compat guests From: Igor Druzhinin The compat layer for multi-extent memory ops may need to split incoming requests. Since the guest handles in the interface structures may not be altered, it does so by leveraging do_memory_op()'s continuation handling: It hands on non-initial requests with a non-zero start extent, with the (native) handle suitably adjusted down. As a result do_memory_op() sees only the first of potentially several requests with start extent being zero. It's only that case when the function would issue a call to pv_shim_online_memory(), yet the range then covers only the first sub-range that results from the split. Address that breakage by making a complementary call to pv_shim_online_memory() in compat layer. Fixes: b2245acc60c3 ("xen/pvshim: memory hotplug") Signed-off-by: Igor Druzhinin Signed-off-by: Jan Beulich Acked-by: Andrew Cooper Release-acked-by: Henry Wang --- diff --git a/xen/common/compat/memory.c b/xen/common/compat/memory.c index 56c7de1dea..8ca63ceda6 100644 --- a/xen/common/compat/memory.c +++ b/xen/common/compat/memory.c @@ -7,6 +7,7 @@ EMIT_FILE; #include #include #include +#include #include #define xen_domid_t domid_t @@ -146,7 +147,10 @@ int compat_memory_op(unsigned int cmd, XEN_GUEST_HANDLE_PARAM(void) compat) nat.rsrv->nr_extents = end_extent; ++split; } - + /* Avoid calling pv_shim_online_memory() when in a continuation. */ + if ( pv_shim && op != XENMEM_decrease_reservation && !start_extent ) + pv_shim_online_memory(cmp.rsrv.nr_extents - nat.rsrv->nr_extents, + cmp.rsrv.extent_order); break; case XENMEM_exchange: