On Fri, Jan 28, 2022 at 12:18:15PM +0000, Marc Zyngier wrote: > From: Jintack Lim <jintack.lim@xxxxxxxxxx> > > ARM v8.3 introduces a new bit in the HCR_EL2, which is the NV bit. When > this bit is set, accessing EL2 registers in EL1 traps to EL2. In > addition, executing the following instructions in EL1 will trap to EL2: > tlbi, at, eret, and msr/mrs instructions to access SP_EL1. Most of the > instructions that trap to EL2 with the NV bit were undef at EL1 prior to > ARM v8.3. The only instruction that was not undef is eret. > > This patch sets up a handler for EL2 registers and SP_EL1 register > accesses at EL1. The host hypervisor keeps those register values in > memory, and will emulate their behavior. > > This patch doesn't set the NV bit yet. It will be set in a later patch > once nested virtualization support is completed. > > Signed-off-by: Jintack Lim <jintack.lim@xxxxxxxxxx> > [maz: EL2_REG() macros] > Signed-off-by: Marc Zyngier <maz@xxxxxxxxxx> Reviewed-by: Russell King (Oracle) <rmk+kernel@xxxxxxxxxxxxxxx> Thanks! -- RMK's Patch system: https://www.armlinux.org.uk/developer/patches/ FTTP is here! 40Mbps down 10Mbps up. Decent connectivity at last!
