This is a small series getting rid of paravirt patching by switching completely to alternative patching for the same functionality.
The basic idea is to add the capability to switch from indirect to direct calls via a special alternative patching option. This removes _some_ of the paravirt macro maze, but most of it needs to stay due to the need of hiding the call instructions from the compiler in order to avoid needless register save/restore. What is going away is the nasty stacking of alternative and paravirt patching and (of course) the special .parainstructions linker section. I have tested the series on bare metal and as Xen PV domain to still work. Note that objtool might need some changes to cope with the new indirect call patching mechanism. Additionally some paravirt handling can probably be removed from it. Changes in V4: - addressed Boris' comments in patch 1 - fixed bugs found by kernel test robot (patch 2) Changes in V3: - split v2 patch 3 into 2 patches as requested by Peter and Ingo Changes in V2: - split last patch into 2 - rebase of patch 2 as suggested by Peter - addressed Peter's comments for patch 3 Juergen Gross (5): x86/paravirt: move some functions and defines to alternative x86/alternative: add indirect call patching x86/paravirt: introduce ALT_NOT_XEN x86/paravirt: switch mixed paravirt/alternative calls to alternative_2 x86/paravirt: remove no longer needed paravirt patching code arch/x86/include/asm/alternative.h | 30 +++++- arch/x86/include/asm/paravirt.h | 79 ++++---------- arch/x86/include/asm/paravirt_types.h | 73 +++---------- arch/x86/include/asm/qspinlock_paravirt.h | 4 +- arch/x86/include/asm/text-patching.h | 12 --- arch/x86/kernel/alternative.c | 121 ++++++++++------------ arch/x86/kernel/callthunks.c | 17 ++- arch/x86/kernel/kvm.c | 4 +- arch/x86/kernel/module.c | 20 +--- arch/x86/kernel/paravirt.c | 54 ++-------- arch/x86/kernel/vmlinux.lds.S | 13 --- arch/x86/tools/relocs.c | 2 +- arch/x86/xen/irq.c | 2 +- 13 files changed, 146 insertions(+), 285 deletions(-) -- 2.35.3 _______________________________________________ Virtualization mailing list Virtualization@lists.linux-foundation.org https://lists.linuxfoundation.org/mailman/listinfo/virtualization
