[PATCH v9 05/11] arm/arm64: vgic: Introduce VENG0 and VENG1 fields to vmcr struct

On Thu, Dec 08, 2016 at 12:52:39PM +0100, Auger Eric wrote:

Hi Vijay,

On 28/11/2016 15:28, Christoffer Dall wrote:

quoted

On Wed, Nov 23, 2016 at 06:31:52PM +0530, vijay.kilari at gmail.com wrote:

quoted

From: Vijaya Kumar K <redacted>

ICC_VMCR_EL2 supports virtual access to ICC_IGRPEN1_EL1.Enable
and ICC_IGRPEN0_EL1.Enable fields. Add grpen0 and grpen1 member
variables to struct vmcr to support read and write of these fields.

Also refactor vgic_set_vmcr and vgic_get_vmcr() code.
Drop ICH_VMCR_CTLR_SHIFT and ICH_VMCR_CTLR_MASK macros and instead
use ICH_VMCR_EOI* and ICH_VMCR_CBPR* macros
.
Signed-off-by: Vijaya Kumar K <redacted>
---
 include/linux/irqchip/arm-gic-v3.h |  2 --
 virt/kvm/arm/vgic/vgic-mmio-v2.c   | 16 ----------------
 virt/kvm/arm/vgic/vgic-mmio.c      | 16 ++++++++++++++++
 virt/kvm/arm/vgic/vgic-v3.c        | 22 ++++++++++++++++++++--
 virt/kvm/arm/vgic/vgic.h           |  5 +++++
 5 files changed, 41 insertions(+), 20 deletions(-)

diff --git a/include/linux/irqchip/arm-gic-v3.h b/include/linux/irqchip/arm-gic-v3.h
index b4f8287..406fc3e 100644
--- a/include/linux/irqchip/arm-gic-v3.h
+++ b/include/linux/irqchip/arm-gic-v3.h

@@ -404,8 +404,6 @@
 #define ICH_HCR_EN			(1 << 0)
 #define ICH_HCR_UIE			(1 << 1)
 
-#define ICH_VMCR_CTLR_SHIFT		0
-#define ICH_VMCR_CTLR_MASK		(0x21f << ICH_VMCR_CTLR_SHIFT)
 #define ICH_VMCR_CBPR_SHIFT		4
 #define ICH_VMCR_CBPR_MASK		(1 << ICH_VMCR_CBPR_SHIFT)
 #define ICH_VMCR_EOIM_SHIFT		9

diff --git a/virt/kvm/arm/vgic/vgic-mmio-v2.c b/virt/kvm/arm/vgic/vgic-mmio-v2.c
index 2cb04b7..ad353b5 100644
--- a/virt/kvm/arm/vgic/vgic-mmio-v2.c
+++ b/virt/kvm/arm/vgic/vgic-mmio-v2.c

@@ -212,22 +212,6 @@ static void vgic_mmio_write_sgipends(struct kvm_vcpu *vcpu,
 	}
 }
 
-static void vgic_set_vmcr(struct kvm_vcpu *vcpu, struct vgic_vmcr *vmcr)
-{
-	if (kvm_vgic_global_state.type == VGIC_V2)
-		vgic_v2_set_vmcr(vcpu, vmcr);
-	else
-		vgic_v3_set_vmcr(vcpu, vmcr);
-}
-
-static void vgic_get_vmcr(struct kvm_vcpu *vcpu, struct vgic_vmcr *vmcr)
-{
-	if (kvm_vgic_global_state.type == VGIC_V2)
-		vgic_v2_get_vmcr(vcpu, vmcr);
-	else
-		vgic_v3_get_vmcr(vcpu, vmcr);
-}
-
 #define GICC_ARCH_VERSION_V2	0x2
 
 /* These are for userland accesses only, there is no guest-facing emulation. */

diff --git a/virt/kvm/arm/vgic/vgic-mmio.c b/virt/kvm/arm/vgic/vgic-mmio.c
index 0d1bc98..f81e0e5 100644
--- a/virt/kvm/arm/vgic/vgic-mmio.c
+++ b/virt/kvm/arm/vgic/vgic-mmio.c

@@ -416,6 +416,22 @@ int vgic_validate_mmio_region_addr(struct kvm_device *dev,
 	return -ENXIO;
 }
 
+void vgic_set_vmcr(struct kvm_vcpu *vcpu, struct vgic_vmcr *vmcr)
+{
+	if (kvm_vgic_global_state.type == VGIC_V2)
+		vgic_v2_set_vmcr(vcpu, vmcr);
+	else
+		vgic_v3_set_vmcr(vcpu, vmcr);
+}
+
+void vgic_get_vmcr(struct kvm_vcpu *vcpu, struct vgic_vmcr *vmcr)
+{
+	if (kvm_vgic_global_state.type == VGIC_V2)
+		vgic_v2_get_vmcr(vcpu, vmcr);
+	else
+		vgic_v3_get_vmcr(vcpu, vmcr);
+}
+
 /*
  * kvm_mmio_read_buf() returns a value in a format where it can be converted
  * to a byte array and be directly observed as the guest wanted it to appear

diff --git a/virt/kvm/arm/vgic/vgic-v3.c b/virt/kvm/arm/vgic/vgic-v3.c
index 9f0dae3..a3ff04b 100644
--- a/virt/kvm/arm/vgic/vgic-v3.c
+++ b/virt/kvm/arm/vgic/vgic-v3.c

@@ -175,10 +175,19 @@ void vgic_v3_set_vmcr(struct kvm_vcpu *vcpu, struct vgic_vmcr *vmcrp)
 {
 	u32 vmcr;
 
-	vmcr  = (vmcrp->ctlr << ICH_VMCR_CTLR_SHIFT) & ICH_VMCR_CTLR_MASK;
+	/*
+	 * Ignore the FIQen bit, because GIC emulation always implies
+	 * SRE=1 which means the vFIQEn bit is also RES1.
+	 */
+	vmcr = (vmcrp->ctlr & ICC_CTLR_EL1_EOImode_MASK) >>
+		ICC_CTLR_EL1_EOImode_SHIFT;
+	vmcr = (vmcr << ICH_VMCR_EOIM_SHIFT) & ICH_VMCR_EOIM_MASK;

I am not able to understand why we use ICC_CTLR _*macros here? Please
could you explain it to me? Besides if we want to ignore the FIQen bit
can't we change the ICH_VMCR_CTLR_MASK value?

This first statement is setting the vmcr to the ctlr's bit[1], but
placed in bit[0], and then the next statement is moving that bit value
to the corresponding place in the vmcr.  I think this is correct
(although a little opaque).

There's also a newer series on the list, just so you know.

Thanks,
-Christoffer