arm64: KVM: VHE: Split save/restore of registers shared between guest and host

A handful of system registers are still shared between host and guest,
even while using VHE (tpidr*_el[01] and actlr_el1).

Also, some of the vcpu state (sp_el0, PC and PSTATE) must be
save/restored on entry/exit, as they are used on the host as well.

In order to facilitate the introduction of a VHE-specific sysreg
save/restore, make move the access to these registers to their
own save/restore functions.

No functional change.

Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>

diff --git a/arch/arm64/kvm/hyp/sysreg-sr.c b/arch/arm64/kvm/hyp/sysreg-sr.c
index bd5b543..61bad17 100644 (file)
--- a/arch/arm64/kvm/hyp/sysreg-sr.c
+++ b/arch/arm64/kvm/hyp/sysreg-sr.c
@@ -23,13 +23,29 @@
 
 #include "hyp.h"
 
-/* ctxt is already in the HYP VA space */
+/*
+ * Non-VHE: Both host and guest must save everything.
+ *
+ * VHE: Host must save tpidr*_el[01], actlr_el1, sp0, pc, pstate, and
+ * guest must save everything.
+ */
+
+static void __hyp_text __sysreg_save_common_state(struct kvm_cpu_context *ctxt)
+{
+       ctxt->sys_regs[ACTLR_EL1]       = read_sysreg(actlr_el1);
+       ctxt->sys_regs[TPIDR_EL0]       = read_sysreg(tpidr_el0);
+       ctxt->sys_regs[TPIDRRO_EL0]     = read_sysreg(tpidrro_el0);
+       ctxt->sys_regs[TPIDR_EL1]       = read_sysreg(tpidr_el1);
+       ctxt->gp_regs.regs.sp           = read_sysreg(sp_el0);
+       ctxt->gp_regs.regs.pc           = read_sysreg(elr_el2);
+       ctxt->gp_regs.regs.pstate       = read_sysreg(spsr_el2);
+}
+
 static void __hyp_text __sysreg_save_state(struct kvm_cpu_context *ctxt)
 {
        ctxt->sys_regs[MPIDR_EL1]       = read_sysreg(vmpidr_el2);
        ctxt->sys_regs[CSSELR_EL1]      = read_sysreg(csselr_el1);
        ctxt->sys_regs[SCTLR_EL1]       = read_sysreg(sctlr_el1);
-       ctxt->sys_regs[ACTLR_EL1]       = read_sysreg(actlr_el1);
        ctxt->sys_regs[CPACR_EL1]       = read_sysreg(cpacr_el1);
        ctxt->sys_regs[TTBR0_EL1]       = read_sysreg(ttbr0_el1);
        ctxt->sys_regs[TTBR1_EL1]       = read_sysreg(ttbr1_el1);
@@ -41,17 +57,11 @@ static void __hyp_text __sysreg_save_state(struct kvm_cpu_context *ctxt)
        ctxt->sys_regs[MAIR_EL1]        = read_sysreg(mair_el1);
        ctxt->sys_regs[VBAR_EL1]        = read_sysreg(vbar_el1);
        ctxt->sys_regs[CONTEXTIDR_EL1]  = read_sysreg(contextidr_el1);
-       ctxt->sys_regs[TPIDR_EL0]       = read_sysreg(tpidr_el0);
-       ctxt->sys_regs[TPIDRRO_EL0]     = read_sysreg(tpidrro_el0);
-       ctxt->sys_regs[TPIDR_EL1]       = read_sysreg(tpidr_el1);
        ctxt->sys_regs[AMAIR_EL1]       = read_sysreg(amair_el1);
        ctxt->sys_regs[CNTKCTL_EL1]     = read_sysreg(cntkctl_el1);
        ctxt->sys_regs[PAR_EL1]         = read_sysreg(par_el1);
        ctxt->sys_regs[MDSCR_EL1]       = read_sysreg(mdscr_el1);
 
-       ctxt->gp_regs.regs.sp           = read_sysreg(sp_el0);
-       ctxt->gp_regs.regs.pc           = read_sysreg(elr_el2);
-       ctxt->gp_regs.regs.pstate       = read_sysreg(spsr_el2);
        ctxt->gp_regs.sp_el1            = read_sysreg(sp_el1);
        ctxt->gp_regs.elr_el1           = read_sysreg(elr_el1);
        ctxt->gp_regs.spsr[KVM_SPSR_EL1]= read_sysreg(spsr_el1);
@@ -60,11 +70,24 @@ static void __hyp_text __sysreg_save_state(struct kvm_cpu_context *ctxt)
 void __hyp_text __sysreg_save_host_state(struct kvm_cpu_context *ctxt)
 {
        __sysreg_save_state(ctxt);
+       __sysreg_save_common_state(ctxt);
 }
 
 void __hyp_text __sysreg_save_guest_state(struct kvm_cpu_context *ctxt)
 {
        __sysreg_save_state(ctxt);
+       __sysreg_save_common_state(ctxt);
+}
+
+static void __hyp_text __sysreg_restore_common_state(struct kvm_cpu_context *ctxt)
+{
+       write_sysreg(ctxt->sys_regs[ACTLR_EL1],   actlr_el1);
+       write_sysreg(ctxt->sys_regs[TPIDR_EL0],   tpidr_el0);
+       write_sysreg(ctxt->sys_regs[TPIDRRO_EL0], tpidrro_el0);
+       write_sysreg(ctxt->sys_regs[TPIDR_EL1],   tpidr_el1);
+       write_sysreg(ctxt->gp_regs.regs.sp,       sp_el0);
+       write_sysreg(ctxt->gp_regs.regs.pc,       elr_el2);
+       write_sysreg(ctxt->gp_regs.regs.pstate,   spsr_el2);
 }
 
 static void __hyp_text __sysreg_restore_state(struct kvm_cpu_context *ctxt)
@@ -72,7 +95,6 @@ static void __hyp_text __sysreg_restore_state(struct kvm_cpu_context *ctxt)
        write_sysreg(ctxt->sys_regs[MPIDR_EL1],   vmpidr_el2);
        write_sysreg(ctxt->sys_regs[CSSELR_EL1],  csselr_el1);
        write_sysreg(ctxt->sys_regs[SCTLR_EL1],   sctlr_el1);
-       write_sysreg(ctxt->sys_regs[ACTLR_EL1],   actlr_el1);
        write_sysreg(ctxt->sys_regs[CPACR_EL1],   cpacr_el1);
        write_sysreg(ctxt->sys_regs[TTBR0_EL1],   ttbr0_el1);
        write_sysreg(ctxt->sys_regs[TTBR1_EL1],   ttbr1_el1);
@@ -84,17 +106,11 @@ static void __hyp_text __sysreg_restore_state(struct kvm_cpu_context *ctxt)
        write_sysreg(ctxt->sys_regs[MAIR_EL1],    mair_el1);
        write_sysreg(ctxt->sys_regs[VBAR_EL1],    vbar_el1);
        write_sysreg(ctxt->sys_regs[CONTEXTIDR_EL1], contextidr_el1);
-       write_sysreg(ctxt->sys_regs[TPIDR_EL0],   tpidr_el0);
-       write_sysreg(ctxt->sys_regs[TPIDRRO_EL0], tpidrro_el0);
-       write_sysreg(ctxt->sys_regs[TPIDR_EL1],   tpidr_el1);
        write_sysreg(ctxt->sys_regs[AMAIR_EL1],   amair_el1);
        write_sysreg(ctxt->sys_regs[CNTKCTL_EL1], cntkctl_el1);
        write_sysreg(ctxt->sys_regs[PAR_EL1],     par_el1);
        write_sysreg(ctxt->sys_regs[MDSCR_EL1],   mdscr_el1);
 
-       write_sysreg(ctxt->gp_regs.regs.sp,     sp_el0);
-       write_sysreg(ctxt->gp_regs.regs.pc,     elr_el2);
-       write_sysreg(ctxt->gp_regs.regs.pstate, spsr_el2);
        write_sysreg(ctxt->gp_regs.sp_el1,      sp_el1);
        write_sysreg(ctxt->gp_regs.elr_el1,     elr_el1);
        write_sysreg(ctxt->gp_regs.spsr[KVM_SPSR_EL1], spsr_el1);
@@ -103,11 +119,13 @@ static void __hyp_text __sysreg_restore_state(struct kvm_cpu_context *ctxt)
 void __hyp_text __sysreg_restore_host_state(struct kvm_cpu_context *ctxt)
 {
        __sysreg_restore_state(ctxt);
+       __sysreg_restore_common_state(ctxt);
 }
 
 void __hyp_text __sysreg_restore_guest_state(struct kvm_cpu_context *ctxt)
 {
        __sysreg_restore_state(ctxt);
+       __sysreg_restore_common_state(ctxt);
 }
 
 void __hyp_text __sysreg32_save_state(struct kvm_vcpu *vcpu)