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[v2] KVM: arm64: pass vcpu esr_el2 and far_el2 sysre to user space

Message ID 1502133454-5905-1-git-send-email-gengdongjiu@huawei.com (mailing list archive)
State New, archived
Headers show

Commit Message

Dongjiu Geng Aug. 7, 2017, 7:17 p.m. UTC 
For the firmware-first RAS solution, SEA and SEI is injected
by the user space, user space needs to know the vcpu's esr_el2 and
far_el2 value, so add them to sysreg. user space uses
the IOCTL KVM_GET_ONE_REG can get their value.

Signed-off-by: Dongjiu Geng <gengdongjiu@huawei.com>
---
 arch/arm64/include/asm/kvm_host.h | 6 ++++--
 arch/arm64/include/asm/sysreg.h   | 2 ++
 arch/arm64/kvm/hyp/switch.c       | 2 ++
 arch/arm64/kvm/sys_regs.c         | 2 ++
 4 files changed, 10 insertions(+), 2 deletions(-)

Comments

Marc Zyngier Aug. 7, 2017, 7:07 p.m. UTC | #1 
On Tue, Aug 08 2017 at  3:17:34 am BST, Dongjiu Geng <gengdongjiu@huawei.com> wrote:
> For the firmware-first RAS solution, SEA and SEI is injected
> by the user space, user space needs to know the vcpu's esr_el2 and
> far_el2 value, so add them to sysreg. user space uses
> the IOCTL KVM_GET_ONE_REG can get their value.

Are we playing a game here? Look at my earlier reply: No _EL2 register
will ever be exposed as such to userspace in the context of an EL1 VM.

So if you want that information, extract it, expose what is required,
strictly what is required, and only when it is required.

In the meantime, I'm NAKing this patch, and any patch that will expose
_EL2 registers outside of nested virtualization.

	M.
Dongjiu Geng Aug. 7, 2017, 11:53 p.m. UTC | #2 
Marc,

On 2017/8/8 3:07, Marc Zyngier wrote:
> So if you want that information, extract it, expose what is required,
> strictly what is required, and only when it is required.
> 
> In the meantime, I'm NAKing this patch, and any patch that will expose
> _EL2 registers outside of nested virtualization.
Thanks for your comments, I will follow your suggestion.
diff mbox

Patch

diff --git a/arch/arm64/include/asm/kvm_host.h b/arch/arm64/include/asm/kvm_host.h
index d68630007b14..075ff9fba0af 100644
--- a/arch/arm64/include/asm/kvm_host.h
+++ b/arch/arm64/include/asm/kvm_host.h
@@ -104,10 +104,12 @@  enum vcpu_sysreg {
 	TTBR0_EL1,	/* Translation Table Base Register 0 */
 	TTBR1_EL1,	/* Translation Table Base Register 1 */
 	TCR_EL1,	/* Translation Control Register */
-	ESR_EL1,	/* Exception Syndrome Register */
+	ESR_EL1,	/* Exception Syndrome Register for EL1 */
+	ESR_EL2,        /* Exception Syndrome Register for EL2 */
 	AFSR0_EL1,	/* Auxiliary Fault Status Register 0 */
 	AFSR1_EL1,	/* Auxiliary Fault Status Register 1 */
-	FAR_EL1,	/* Fault Address Register */
+	FAR_EL1,	/* Fault Address Register for EL1 */
+	FAR_EL2,        /* Fault Address Register for EL2 */
 	MAIR_EL1,	/* Memory Attribute Indirection Register */
 	VBAR_EL1,	/* Vector Base Address Register */
 	CONTEXTIDR_EL1,	/* Context ID Register */
diff --git a/arch/arm64/include/asm/sysreg.h b/arch/arm64/include/asm/sysreg.h
index 248339e4aaf5..b019141a8c29 100644
--- a/arch/arm64/include/asm/sysreg.h
+++ b/arch/arm64/include/asm/sysreg.h
@@ -252,7 +252,9 @@ 
 
 #define SYS_DACR32_EL2			sys_reg(3, 4, 3, 0, 0)
 #define SYS_IFSR32_EL2			sys_reg(3, 4, 5, 0, 1)
+#define SYS_ESR_EL2			sys_reg(3, 4, 5, 2, 0)
 #define SYS_FPEXC32_EL2			sys_reg(3, 4, 5, 3, 0)
+#define SYS_FAR_EL2			sys_reg(3, 4, 6, 0, 0)
 
 #define __SYS__AP0Rx_EL2(x)		sys_reg(3, 4, 12, 8, x)
 #define SYS_ICH_AP0R0_EL2		__SYS__AP0Rx_EL2(0)
diff --git a/arch/arm64/kvm/hyp/switch.c b/arch/arm64/kvm/hyp/switch.c
index c6f17c7675ad..6ec9ecd68d20 100644
--- a/arch/arm64/kvm/hyp/switch.c
+++ b/arch/arm64/kvm/hyp/switch.c
@@ -229,6 +229,7 @@  static bool __hyp_text __translate_far_to_hpfar(u64 far, u64 *hpfar)
 static void __hyp_text __populate_fault_info_esr(struct kvm_vcpu *vcpu)
 {
 	vcpu->arch.fault.esr_el2 = read_sysreg_el2(esr);
+	vcpu_sys_reg(vcpu,ESR_EL2) = read_sysreg_el2(esr);
 }
 
 static bool __hyp_text __populate_fault_info(struct kvm_vcpu *vcpu)
@@ -267,6 +268,7 @@  static bool __hyp_text __populate_fault_info(struct kvm_vcpu *vcpu)
 
 	vcpu->arch.fault.far_el2 = far;
 	vcpu->arch.fault.hpfar_el2 = hpfar;
+	vcpu_sys_reg(vcpu,FAR_EL2) = far;
 	return true;
 }
 
diff --git a/arch/arm64/kvm/sys_regs.c b/arch/arm64/kvm/sys_regs.c
index 2e070d3baf9f..c730d593efbb 100644
--- a/arch/arm64/kvm/sys_regs.c
+++ b/arch/arm64/kvm/sys_regs.c
@@ -1079,7 +1079,9 @@  static const struct sys_reg_desc sys_reg_descs[] = {
 
 	{ SYS_DESC(SYS_DACR32_EL2), NULL, reset_unknown, DACR32_EL2 },
 	{ SYS_DESC(SYS_IFSR32_EL2), NULL, reset_unknown, IFSR32_EL2 },
+	{ SYS_DESC(SYS_ESR_EL2), access_vm_reg, reset_unknown, ESR_EL2 },
 	{ SYS_DESC(SYS_FPEXC32_EL2), NULL, reset_val, FPEXC32_EL2, 0x70 },
+	{ SYS_DESC(SYS_FAR_EL2), access_vm_reg, reset_unknown, FAR_EL2 },
 };
 
 static bool trap_dbgidr(struct kvm_vcpu *vcpu,