From: James Morse <james.morse@arm•com>
To: kvmarm@lists•cs.columbia.edu, linux-arm-kernel@lists•infradead.org
Cc: Marc Zyngier <maz@kernel•org>,
Julien Thierry <julien.thierry.kdev@gmail•com>,
Suzuki K Poulose <suzuki.poulose@arm•com>
Subject: [PATCH v2 3/3] KVM: arm64: Stop save/restoring ACTLR_EL1
Date: Fri, 29 May 2020 15:06:56 +0000 [thread overview]
Message-ID: <20200529150656.7339-4-james.morse@arm.com> (raw)
In-Reply-To: <20200529150656.7339-1-james.morse@arm.com>
KVM sets HCR_EL2.TACR via HCR_GUEST_FLAGS. This means ACTLR* accesses
from the guest are always trapped, and always return the value in the
sys_regs array.
The guest can't change the value of these registers, so we are
save restoring the reset value, which came from the host.
Stop save/restoring this register. Keep the storage for this register
in sys_regs[] as this is how the value is exposed to user-space,
removing it would break migration.
Signed-off-by: James Morse <james.morse@arm•com>
---
arch/arm64/kvm/hyp/sysreg-sr.c | 2 --
arch/arm64/kvm/sys_regs.c | 2 --
2 files changed, 4 deletions(-)
diff --git a/arch/arm64/kvm/hyp/sysreg-sr.c b/arch/arm64/kvm/hyp/sysreg-sr.c
index 75b1925763f1..57116cf3a1a5 100644
--- a/arch/arm64/kvm/hyp/sysreg-sr.c
+++ b/arch/arm64/kvm/hyp/sysreg-sr.c
@@ -44,7 +44,6 @@ static void __hyp_text __sysreg_save_el1_state(struct kvm_cpu_context *ctxt)
{
ctxt->sys_regs[CSSELR_EL1] = read_sysreg(csselr_el1);
ctxt->sys_regs[SCTLR_EL1] = read_sysreg_el1(SYS_SCTLR);
- ctxt->sys_regs[ACTLR_EL1] = read_sysreg(actlr_el1);
ctxt->sys_regs[CPACR_EL1] = read_sysreg_el1(SYS_CPACR);
ctxt->sys_regs[TTBR0_EL1] = read_sysreg_el1(SYS_TTBR0);
ctxt->sys_regs[TTBR1_EL1] = read_sysreg_el1(SYS_TTBR1);
@@ -133,7 +132,6 @@ static void __hyp_text __sysreg_restore_el1_state(struct kvm_cpu_context *ctxt)
isb();
}
- write_sysreg(ctxt->sys_regs[ACTLR_EL1], actlr_el1);
write_sysreg_el1(ctxt->sys_regs[CPACR_EL1], SYS_CPACR);
write_sysreg_el1(ctxt->sys_regs[TTBR0_EL1], SYS_TTBR0);
write_sysreg_el1(ctxt->sys_regs[TTBR1_EL1], SYS_TTBR1);
diff --git a/arch/arm64/kvm/sys_regs.c b/arch/arm64/kvm/sys_regs.c
index bfd68cd4fc54..545bc18b9c24 100644
--- a/arch/arm64/kvm/sys_regs.c
+++ b/arch/arm64/kvm/sys_regs.c
@@ -81,7 +81,6 @@ u64 vcpu_read_sys_reg(const struct kvm_vcpu *vcpu, int reg)
switch (reg) {
case CSSELR_EL1: return read_sysreg_s(SYS_CSSELR_EL1);
case SCTLR_EL1: return read_sysreg_s(SYS_SCTLR_EL12);
- case ACTLR_EL1: return read_sysreg_s(SYS_ACTLR_EL1);
case CPACR_EL1: return read_sysreg_s(SYS_CPACR_EL12);
case TTBR0_EL1: return read_sysreg_s(SYS_TTBR0_EL12);
case TTBR1_EL1: return read_sysreg_s(SYS_TTBR1_EL12);
@@ -124,7 +123,6 @@ void vcpu_write_sys_reg(struct kvm_vcpu *vcpu, u64 val, int reg)
switch (reg) {
case CSSELR_EL1: write_sysreg_s(val, SYS_CSSELR_EL1); return;
case SCTLR_EL1: write_sysreg_s(val, SYS_SCTLR_EL12); return;
- case ACTLR_EL1: write_sysreg_s(val, SYS_ACTLR_EL1); return;
case CPACR_EL1: write_sysreg_s(val, SYS_CPACR_EL12); return;
case TTBR0_EL1: write_sysreg_s(val, SYS_TTBR0_EL12); return;
case TTBR1_EL1: write_sysreg_s(val, SYS_TTBR1_EL12); return;
--
2.20.1
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next prev parent reply other threads:[~2020-05-29 15:08 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-05-29 15:06 [PATCH v2 0/3] KVM: arm64: aarch32 ACTLR accesses James Morse
2020-05-29 15:06 ` [PATCH v2 1/3] KVM: arm64: Stop writing aarch32's CSSELR into ACTLR James Morse
2020-05-29 15:06 ` [PATCH v2 2/3] KVM: arm64: Add emulation for 32bit guests accessing ACTLR2 James Morse
2020-05-29 15:06 ` James Morse [this message]
2020-06-10 13:17 ` [PATCH v2 0/3] KVM: arm64: aarch32 ACTLR accesses Marc Zyngier
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