From: Hu Huajun <huhuajun@huawei.com>
To: <christoffer.dall@linaro.org>, <marc.zyngier@arm.com>,
        <rkrcmar@redhat.com>
CC: <linux-arm-kernel@lists.infradead.org>, <kvmarm@lists.cs.columbia.edu>,
        <kvm@vger.kernel.org>, <linux-kernel@vger.kernel.org>,
        <songwenjun@huawei.com>, <gengdongjiu@huawei.com>,
        <huhuajun@huawei.com>
Subject: [PATCH v2] KVM: ARM64: fix phy counter access failure in guest.
Date: Mon, 12 Jun 2017 22:37:48 +0800
Message-ID: <20170612143748.37278-1-huhuajun@huawei.com>
MIME-Version: 1.0
Content-Type: text/plain
Sender: linux-kernel-owner@vger.kernel.org
Content-Length: 1378
Lines: 42

When reading the cntpct_el0 in guest with VHE (Virtual Host Extension)
enabled in host, the "Unsupported guest sys_reg access" error reported.
The reason is cnthctl_el2.EL1PCTEN is not enabled, which is expected
to be done in kvm_timer_init_vhe(). The problem is kvm_timer_init_vhe
is called by cpu_init_hyp_mode, and which is called when VHE is disabled.
This patch remove the incorrect call to kvm_timer_init_vhe() from
cpu_init_hyp_mode(), and calls kvm_timer_init_vhe() to enable
cnthctl_el2.EL1PCTEN in cpu_hyp_reinit().

Changes from v1:
* According to Christoffer Dall's comment, remove the incocrrect call
to kvm_timer_init_vhe() in cpu_init_hyp_mode().

Signed-off-by: Hu Huajun <huhuajun@huawei.com>
---
 virt/kvm/arm/arm.c | 4 +---
 1 file changed, 1 insertion(+), 3 deletions(-)

diff --git a/virt/kvm/arm/arm.c b/virt/kvm/arm/arm.c
index 3417e18..a430125 100644
--- a/virt/kvm/arm/arm.c
+++ b/virt/kvm/arm/arm.c
@@ -1115,9 +1115,6 @@ static void cpu_init_hyp_mode(void *dummy)
 	__cpu_init_hyp_mode(pgd_ptr, hyp_stack_ptr, vector_ptr);
 	__cpu_init_stage2();
 
-	if (is_kernel_in_hyp_mode())
-		kvm_timer_init_vhe();
-
 	kvm_arm_init_debug();
 }
 
@@ -1137,6 +1134,7 @@ static void cpu_hyp_reinit(void)
 		 * event was cancelled before the CPU was reset.
 		 */
 		__cpu_init_stage2();
+		kvm_timer_init_vhe();
 	} else {
 		cpu_init_hyp_mode(NULL);
 	}
-- 
2.10.1