[PATCH v3 11/23] arm64: KVM: VHE: Split save/restore of registers shared between guest and host

Marc Zyngier
2016-02-03T18:05:03Z

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 functionnal change.

Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
---
arch/arm64/kvm/hyp/sysreg-sr.c | 48 +++++++++++++++++++++++++++++-------------
1 file changed, 33 insertions(+), 15 deletions(-)

diff --git a/arch/arm64/kvm/hyp/sysreg-sr.c b/arch/arm64/kvm/hyp/sysreg-sr.c
index bd5b543..61bad17 100644
--- 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)
--
2.1.4