From mboxrd@z Thu Jan 1 00:00:00 1970 From: cdall@linaro.org (Christoffer Dall) Date: Sun, 3 Dec 2017 20:51:45 +0100 Subject: [PATCH 24/37] KVM: arm64: Prepare to handle traps on deferred EL0 sysregs In-Reply-To: References: <20171012104141.26902-1-christoffer.dall@linaro.org> <20171012104141.26902-25-christoffer.dall@linaro.org> Message-ID: <20171203195145.GJ4218@cbox> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On Wed, Nov 15, 2017 at 09:25:08AM +0000, Julien Thierry wrote: > > > On 12/10/17 11:41, Christoffer Dall wrote: > >We can trap access to ACTLR_EL1 which we can later defer to only > >save/restore during vcpu_load and vcpu_put, so let's read the value > >directly from the CPU when necessary. > > > >Signed-off-by: Christoffer Dall > >--- > > arch/arm64/kvm/sys_regs_generic_v8.c | 5 ++++- > > 1 file changed, 4 insertions(+), 1 deletion(-) > > > >diff --git a/arch/arm64/kvm/sys_regs_generic_v8.c b/arch/arm64/kvm/sys_regs_generic_v8.c > >index 969ade1..348f227 100644 > >--- a/arch/arm64/kvm/sys_regs_generic_v8.c > >+++ b/arch/arm64/kvm/sys_regs_generic_v8.c > >@@ -38,7 +38,10 @@ static bool access_actlr(struct kvm_vcpu *vcpu, > > if (p->is_write) > > return ignore_write(vcpu, p); > >- p->regval = vcpu_sys_reg(vcpu, ACTLR_EL1); > >+ if (vcpu->arch.sysregs_loaded_on_cpu) > >+ read_sysreg(actlr_el1); > > Did you mean "p->regval = read_sysreg(actlr_el1);" ? > > >+ else > >+ p->regval = vcpu_sys_reg(vcpu, ACTLR_EL1); > > return true; > > } > > > Yes, most certainly. Nice catch. Thanks, -Christoffer