search for: b2e2a00

.... > > How much does this bloat the kernel? It seems to add 8 bytes to each {wr,rd}msr() call (4 extra instructions: test, jmp, ud2, jmp). allyesconfig, paravirt enabled, before: text data bss dec hex filename 108368312 23500872 55705600 187574784 b2e2a00 vmlinux allyesconfig, paravirt enabled, after: text data bss dec hex filename 108384438 23500904 55717888 187603230 b2e991e vmlinux allyesconfig vmlinux is 28446 bytes larger. An alternative is to add read_msr_unsafe() & write_msr_unsafe() fields...

.... > > How much does this bloat the kernel? It seems to add 8 bytes to each {wr,rd}msr() call (4 extra instructions: test, jmp, ud2, jmp). allyesconfig, paravirt enabled, before: text data bss dec hex filename 108368312 23500872 55705600 187574784 b2e2a00 vmlinux allyesconfig, paravirt enabled, after: text data bss dec hex filename 108384438 23500904 55717888 187603230 b2e991e vmlinux allyesconfig vmlinux is 28446 bytes larger. An alternative is to add read_msr_unsafe() & write_msr_unsafe() fields...

When CONFIG_PARAVIRT is enabled, the kernel is ignoring exceptions on the {rd,wr}msr instructions. This makes serious issues (either on the guest kernel, or on the host) be silently ignored, and is different from the native MSR code (which does not ignore the exceptions). As paravirt.h already includes linux/bug.h, I don't see what was the original issue preventing BUG_ON from being used.

When CONFIG_PARAVIRT is enabled, the kernel is ignoring exceptions on the {rd,wr}msr instructions. This makes serious issues (either on the guest kernel, or on the host) be silently ignored, and is different from the native MSR code (which does not ignore the exceptions). As paravirt.h already includes linux/bug.h, I don't see what was the original issue preventing BUG_ON from being used.