KVM: arm64: Stop save/restoring host tpidr_el1 on VHE

Now that a VHE host uses tpidr_el2 for the cpu offset we no longer
need KVM to save/restore tpidr_el1. Move this from the 'common' code
into the non-vhe code. While we're at it, on VHE we don't need to
save the ELR or SPSR as kernel_entry in entry.S will have pushed these
onto the kernel stack, and will restore them from there. Move these
to the non-vhe code as we need them to get back to the host.

Finally remove the always-copy-tpidr we hid in the stage2 setup
code, cpufeature's enable callback will do this for VHE, we only
need KVM to do it for non-vhe. Add the copy into kvm-init instead.

Signed-off-by: James Morse <james.morse@arm.com>
Reviewed-by: Christoffer Dall <cdall@linaro.org>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>

diff --git a/arch/arm64/kvm/hyp-init.S b/arch/arm64/kvm/hyp-init.S
index 33c40b3..8a00de1 100644 (file)
--- a/arch/arm64/kvm/hyp-init.S
+++ b/arch/arm64/kvm/hyp-init.S
@@ -120,6 +120,10 @@ CPU_BE(    orr     x4, x4, #SCTLR_ELx_EE)
        kern_hyp_va     x2
        msr     vbar_el2, x2
 
+       /* copy tpidr_el1 into tpidr_el2 for use by HYP */
+       mrs     x1, tpidr_el1
+       msr     tpidr_el2, x1
+
        /* Hello, World! */
        eret
 ENDPROC(__kvm_hyp_init)

diff --git a/arch/arm64/kvm/hyp/s2-setup.c b/arch/arm64/kvm/hyp/s2-setup.c
index 74306c3..603e1ee 100644 (file)
--- a/arch/arm64/kvm/hyp/s2-setup.c
+++ b/arch/arm64/kvm/hyp/s2-setup.c
@@ -86,8 +86,5 @@ u32 __hyp_text __init_stage2_translation(void)
 
        write_sysreg(val, vtcr_el2);
 
-       /* copy tpidr_el1 into tpidr_el2 for use by HYP */
-       write_sysreg(read_sysreg(tpidr_el1), tpidr_el2);
-
        return parange;
 }

diff --git a/arch/arm64/kvm/hyp/sysreg-sr.c b/arch/arm64/kvm/hyp/sysreg-sr.c
index 9341376..c54cc2a 100644 (file)
--- a/arch/arm64/kvm/hyp/sysreg-sr.c
+++ b/arch/arm64/kvm/hyp/sysreg-sr.c
@@ -27,8 +27,8 @@ static void __hyp_text __sysreg_do_nothing(struct kvm_cpu_context *ctxt) { }
 /*
  * Non-VHE: Both host and guest must save everything.
  *
- * VHE: Host must save tpidr*_el[01], actlr_el1, mdscr_el1, sp0, pc,
- * pstate, and guest must save everything.
+ * VHE: Host must save tpidr*_el0, actlr_el1, mdscr_el1, sp_el0,
+ * and guest must save everything.
  */
 
 static void __hyp_text __sysreg_save_common_state(struct kvm_cpu_context *ctxt)
@@ -36,11 +36,8 @@ 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->sys_regs[MDSCR_EL1]       = read_sysreg(mdscr_el1);
        ctxt->gp_regs.regs.sp           = read_sysreg(sp_el0);
-       ctxt->gp_regs.regs.pc           = read_sysreg_el2(elr);
-       ctxt->gp_regs.regs.pstate       = read_sysreg_el2(spsr);
 }
 
 static void __hyp_text __sysreg_save_state(struct kvm_cpu_context *ctxt)
@@ -62,10 +59,13 @@ static void __hyp_text __sysreg_save_state(struct kvm_cpu_context *ctxt)
        ctxt->sys_regs[AMAIR_EL1]       = read_sysreg_el1(amair);
        ctxt->sys_regs[CNTKCTL_EL1]     = read_sysreg_el1(cntkctl);
        ctxt->sys_regs[PAR_EL1]         = read_sysreg(par_el1);
+       ctxt->sys_regs[TPIDR_EL1]       = read_sysreg(tpidr_el1);
 
        ctxt->gp_regs.sp_el1            = read_sysreg(sp_el1);
        ctxt->gp_regs.elr_el1           = read_sysreg_el1(elr);
        ctxt->gp_regs.spsr[KVM_SPSR_EL1]= read_sysreg_el1(spsr);
+       ctxt->gp_regs.regs.pc           = read_sysreg_el2(elr);
+       ctxt->gp_regs.regs.pstate       = read_sysreg_el2(spsr);
 }
 
 static hyp_alternate_select(__sysreg_call_save_host_state,
@@ -89,11 +89,8 @@ static void __hyp_text __sysreg_restore_common_state(struct kvm_cpu_context *ctx
        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->sys_regs[MDSCR_EL1],   mdscr_el1);
        write_sysreg(ctxt->gp_regs.regs.sp,       sp_el0);
-       write_sysreg_el2(ctxt->gp_regs.regs.pc,   elr);
-       write_sysreg_el2(ctxt->gp_regs.regs.pstate, spsr);
 }
 
 static void __hyp_text __sysreg_restore_state(struct kvm_cpu_context *ctxt)
@@ -115,10 +112,13 @@ static void __hyp_text __sysreg_restore_state(struct kvm_cpu_context *ctxt)
        write_sysreg_el1(ctxt->sys_regs[AMAIR_EL1],     amair);
        write_sysreg_el1(ctxt->sys_regs[CNTKCTL_EL1],   cntkctl);
        write_sysreg(ctxt->sys_regs[PAR_EL1],           par_el1);
+       write_sysreg(ctxt->sys_regs[TPIDR_EL1],         tpidr_el1);
 
        write_sysreg(ctxt->gp_regs.sp_el1,              sp_el1);
        write_sysreg_el1(ctxt->gp_regs.elr_el1,         elr);
        write_sysreg_el1(ctxt->gp_regs.spsr[KVM_SPSR_EL1],spsr);
+       write_sysreg_el2(ctxt->gp_regs.regs.pc,         elr);
+       write_sysreg_el2(ctxt->gp_regs.regs.pstate,     spsr);
 }
 
 static hyp_alternate_select(__sysreg_call_restore_host_state,