[PATCH v2 3/3] arm64: kvm: add support for the extended 64bit ccsidr
Sudeep Holla
sudeep.holla at arm.com
Mon Jan 30 08:25:27 PST 2017
csselr and ccsidr are treated as 64-bit values already elsewhere in the
kernel. It also aligns well with the architecture extensions that allow
64-bit format for ccsidr.
This patch upgrades the existing accesses to csselr and ccsidr from
32-bit to 64-bit in preparation to add support to those extensions.
It also add dedicated KVM_REG_ARM_DEMUX_ID_EXT_CCSIDR demux register
to handle 64-bit ccsidr in KVM.
Cc: Christoffer Dall <christoffer.dall at linaro.org>
Cc: Marc Zyngier <marc.zyngier at arm.com>
Signed-off-by: Sudeep Holla <sudeep.holla at arm.com>
---
arch/arm64/include/uapi/asm/kvm.h | 1 +
arch/arm64/kvm/sys_regs.c | 104 ++++++++++++++++++++++++++++----------
2 files changed, 77 insertions(+), 28 deletions(-)
v1->v2:
- Added dependency on cpu_supports_ccsidr_64b_format(PATCH 1/3)
- Added a new KVM_REG_ARM_DEMUX_ID_EXT_CCSIDR demux register id
to support new 64bit CCSIDR
diff --git a/arch/arm64/include/uapi/asm/kvm.h b/arch/arm64/include/uapi/asm/kvm.h
index 3051f86a9b5f..8aa18e65e6a5 100644
--- a/arch/arm64/include/uapi/asm/kvm.h
+++ b/arch/arm64/include/uapi/asm/kvm.h
@@ -161,6 +161,7 @@ struct kvm_arch_memory_slot {
#define KVM_REG_ARM_DEMUX_ID_MASK 0x000000000000FF00
#define KVM_REG_ARM_DEMUX_ID_SHIFT 8
#define KVM_REG_ARM_DEMUX_ID_CCSIDR (0x00 << KVM_REG_ARM_DEMUX_ID_SHIFT)
+#define KVM_REG_ARM_DEMUX_ID_EXT_CCSIDR (0x01 << KVM_REG_ARM_DEMUX_ID_SHIFT)
#define KVM_REG_ARM_DEMUX_VAL_MASK 0x00000000000000FF
#define KVM_REG_ARM_DEMUX_VAL_SHIFT 0
diff --git a/arch/arm64/kvm/sys_regs.c b/arch/arm64/kvm/sys_regs.c
index 72656743b4cc..f9822ac6d9ab 100644
--- a/arch/arm64/kvm/sys_regs.c
+++ b/arch/arm64/kvm/sys_regs.c
@@ -58,15 +58,15 @@
*/
/* 3 bits per cache level, as per CLIDR, but non-existent caches always 0 */
-static u32 cache_levels;
+static u64 cache_levels;
-/* CSSELR values; used to index KVM_REG_ARM_DEMUX_ID_CCSIDR */
+/* CSSELR values; used to index KVM_REG_ARM_DEMUX_ID_{EXT_,}CCSIDR */
#define CSSELR_MAX ((MAX_CACHE_LEVEL - 1) << 1)
/* Which cache CCSIDR represents depends on CSSELR value. */
-static u32 get_ccsidr(u32 csselr)
+static u64 get_ccsidr(u64 csselr)
{
- u32 ccsidr;
+ u64 ccsidr;
/* Make sure noone else changes CSSELR during this! */
local_irq_disable();
@@ -1952,9 +1952,9 @@ static int set_invariant_sys_reg(u64 id, void __user *uaddr)
return 0;
}
-static bool is_valid_cache(u32 val)
+static bool is_valid_cache(u64 val)
{
- u32 level, ctype;
+ u64 level, ctype;
if (val >= CSSELR_MAX)
return false;
@@ -1977,10 +1977,28 @@ static bool is_valid_cache(u32 val)
}
}
+static int demux_ccsidr_validate_get(u64 id, int size, u64 *val)
+{
+ u64 cidx;
+
+ if (KVM_REG_SIZE(id) != size)
+ return -ENOENT;
+
+ cidx = (id & KVM_REG_ARM_DEMUX_VAL_MASK)
+ >> KVM_REG_ARM_DEMUX_VAL_SHIFT;
+ if (!is_valid_cache(cidx))
+ return -ENOENT;
+
+ *val = get_ccsidr(cidx);
+ return 0;
+}
+
static int demux_c15_get(u64 id, void __user *uaddr)
{
- u32 val;
- u32 __user *uval = uaddr;
+ int ret;
+ u64 val;
+ u32 __user *uval;
+ u64 __user *uval64;
/* Fail if we have unknown bits set. */
if (id & ~(KVM_REG_ARCH_MASK|KVM_REG_SIZE_MASK|KVM_REG_ARM_COPROC_MASK
@@ -1989,14 +2007,17 @@ static int demux_c15_get(u64 id, void __user *uaddr)
switch (id & KVM_REG_ARM_DEMUX_ID_MASK) {
case KVM_REG_ARM_DEMUX_ID_CCSIDR:
- if (KVM_REG_SIZE(id) != 4)
- return -ENOENT;
- val = (id & KVM_REG_ARM_DEMUX_VAL_MASK)
- >> KVM_REG_ARM_DEMUX_VAL_SHIFT;
- if (!is_valid_cache(val))
- return -ENOENT;
-
- return put_user(get_ccsidr(val), uval);
+ ret = demux_ccsidr_validate_get(id, sizeof(*uval), &val);
+ if (ret)
+ return ret;
+ uval = uaddr;
+ return put_user(val, uval);
+ case KVM_REG_ARM_DEMUX_ID_EXT_CCSIDR:
+ ret = demux_ccsidr_validate_get(id, sizeof(*uval64), &val);
+ if (ret)
+ return ret;
+ uval64 = uaddr;
+ return put_user(val, uval64);
default:
return -ENOENT;
}
@@ -2004,8 +2025,10 @@ static int demux_c15_get(u64 id, void __user *uaddr)
static int demux_c15_set(u64 id, void __user *uaddr)
{
- u32 val, newval;
- u32 __user *uval = uaddr;
+ int ret;
+ u64 val, newval;
+ u32 __user *uval;
+ u64 __user *uval64;
/* Fail if we have unknown bits set. */
if (id & ~(KVM_REG_ARCH_MASK|KVM_REG_SIZE_MASK|KVM_REG_ARM_COPROC_MASK
@@ -2014,18 +2037,29 @@ static int demux_c15_set(u64 id, void __user *uaddr)
switch (id & KVM_REG_ARM_DEMUX_ID_MASK) {
case KVM_REG_ARM_DEMUX_ID_CCSIDR:
- if (KVM_REG_SIZE(id) != 4)
- return -ENOENT;
- val = (id & KVM_REG_ARM_DEMUX_VAL_MASK)
- >> KVM_REG_ARM_DEMUX_VAL_SHIFT;
- if (!is_valid_cache(val))
- return -ENOENT;
+ ret = demux_ccsidr_validate_get(id, sizeof(*uval), &val);
+ if (ret)
+ return ret;
+ uval = uaddr;
if (get_user(newval, uval))
return -EFAULT;
/* This is also invariant: you can't change it. */
- if (newval != get_ccsidr(val))
+ if (newval != val)
+ return -EINVAL;
+ return 0;
+ case KVM_REG_ARM_DEMUX_ID_EXT_CCSIDR:
+ ret = demux_ccsidr_validate_get(id, sizeof(*uval), &val);
+ if (ret)
+ return ret;
+
+ uval64 = uaddr;
+ if (get_user(newval, uval64))
+ return -EFAULT;
+
+ /* This is also invariant: you can't change it. */
+ if (newval != val)
return -EINVAL;
return 0;
default:
@@ -2086,12 +2120,10 @@ static unsigned int num_demux_regs(void)
return count;
}
-static int write_demux_regids(u64 __user *uindices)
+static int write_demux_ccsidr(u64 val, u64 __user *uindices)
{
- u64 val = KVM_REG_ARM64 | KVM_REG_SIZE_U32 | KVM_REG_ARM_DEMUX;
unsigned int i;
- val |= KVM_REG_ARM_DEMUX_ID_CCSIDR;
for (i = 0; i < CSSELR_MAX; i++) {
if (!is_valid_cache(i))
continue;
@@ -2099,9 +2131,25 @@ static int write_demux_regids(u64 __user *uindices)
return -EFAULT;
uindices++;
}
+
return 0;
}
+static int write_demux_regids(u64 __user *uindices)
+{
+ int ret;
+ u64 val = KVM_REG_ARM64 | KVM_REG_ARM_DEMUX;
+
+ if (cpu_supports_ccsidr_64b_format())
+ /* 64 bit extended CCSIDR */
+ ret = write_demux_ccsidr(val | KVM_REG_ARM_DEMUX_ID_EXT_CCSIDR |
+ KVM_REG_SIZE_U64, uindices);
+ else
+ ret = write_demux_ccsidr(val | KVM_REG_ARM_DEMUX_ID_CCSIDR |
+ KVM_REG_SIZE_U32, uindices);
+ return ret;
+}
+
static u64 sys_reg_to_index(const struct sys_reg_desc *reg)
{
return (KVM_REG_ARM64 | KVM_REG_SIZE_U64 |
--
2.7.4
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