From 02143947603fe90237a0423d34dd8943de229f78 Mon Sep 17 00:00:00 2001 From: Paul Mackerras Date: Sat, 23 Jul 2011 17:41:44 +1000 Subject: KVM: PPC: book3s_pr: Simplify transitions between virtual and real mode This simplifies the way that the book3s_pr makes the transition to real mode when entering the guest. We now call kvmppc_entry_trampoline (renamed from kvmppc_rmcall) in the base kernel using a normal function call instead of doing an indirect call through a pointer in the vcpu. If kvm is a module, the module loader takes care of generating a trampoline as it does for other calls to functions outside the module. kvmppc_entry_trampoline then disables interrupts and jumps to kvmppc_handler_trampoline_enter in real mode using an rfi[d]. That then uses the link register as the address to return to (potentially in module space) when the guest exits. This also simplifies the way that we call the Linux interrupt handler when we exit the guest due to an external, decrementer or performance monitor interrupt. Instead of turning on the MMU, then deciding that we need to call the Linux handler and turning the MMU back off again, we now go straight to the handler at the point where we would turn the MMU on. The handler will then return to the virtual-mode code (potentially in the module). Along the way, this moves the setting and clearing of the HID5 DCBZ32 bit into real-mode interrupts-off code, and also makes sure that we clear the MSR[RI] bit before loading values into SRR0/1. The net result is that we no longer need any code addresses to be stored in vcpu->arch. Signed-off-by: Paul Mackerras Signed-off-by: Alexander Graf --- arch/powerpc/kvm/book3s_32_sr.S | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'arch/powerpc/kvm/book3s_32_sr.S') diff --git a/arch/powerpc/kvm/book3s_32_sr.S b/arch/powerpc/kvm/book3s_32_sr.S index 3608471ad2d8..7e06a6fc8d07 100644 --- a/arch/powerpc/kvm/book3s_32_sr.S +++ b/arch/powerpc/kvm/book3s_32_sr.S @@ -31,7 +31,7 @@ * R1 = host R1 * R2 = host R2 * R3 = shadow vcpu - * all other volatile GPRS = free + * all other volatile GPRS = free except R4, R6 * SVCPU[CR] = guest CR * SVCPU[XER] = guest XER * SVCPU[CTR] = guest CTR -- cgit v1.2.2