On Wed, Jul 09 2014 at 10:45:05 am BST, Christoffer Dall <christoffer.dall@xxxxxxxxxx> wrote: > On Fri, Jun 20, 2014 at 02:00:06PM +0100, Marc Zyngier wrote: >> Implement switching of the debug registers. While the number >> of registers is massive, CPUs usually don't implement them all >> (A57 has 6 breakpoints and 4 watchpoints, which gives us a total >> of 22 registers "only"). >> >> Also, we only save/restore them when MDSCR_EL1 has debug enabled, >> or when we've flagged the debug registers as dirty. It means that >> most of the time, we only save/restore MDSCR_EL1. >> >> Reviewed-by: Anup Patel <anup.patel@xxxxxxxxxx> >> Signed-off-by: Marc Zyngier <marc.zyngier@xxxxxxx> >> --- >> arch/arm64/kernel/asm-offsets.c | 1 + >> arch/arm64/kvm/hyp.S | 462 +++++++++++++++++++++++++++++++++++++++- >> 2 files changed, 457 insertions(+), 6 deletions(-) >> [...] >> @@ -609,6 +1052,13 @@ __kvm_vcpu_return: >> >> bl __restore_sysregs >> bl __restore_fpsimd >> + >> + skip_debug_state x3, 1f >> + // Clear the dirty flag for the next run, as all the state has >> + // already been saved. >> + str xzr, [x0, #VCPU_DEBUG_FLAGS] >> + bl __restore_debug >> +1: >> restore_host_regs >> >> mov x0, x1 >> -- >> 1.8.3.4 >> > > let's just try to remember the fact that we overwrite the entire bitmask > here if we add more bits to that value some time: I'll add a comment to that effect. > Reviewed-by: Christoffer Dall <christoffer.dall@xxxxxxxxxx> Thanks! M. -- Without deviation from the norm, progress is not possible. -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
