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[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] [Xen-devel] [RFC v2 07/12] x86: implement set value flow for MBA.
This patch implements set value flow for MBA including its callback
function and domctl interface.
It also changes the memebers in 'cos_write_info' to transfer the
feature array, feature properties array and value array. Then, we
can write all features values on the cos id into MSRs.
Signed-off-by: Yi Sun <yi.y.sun@xxxxxxxxxxxxxxx>
---
xen/arch/x86/domctl.c | 6 ++
xen/arch/x86/psr.c | 184 ++++++++++++++++++++++++++++++++------------
xen/include/public/domctl.h | 1 +
3 files changed, 143 insertions(+), 48 deletions(-)
diff --git a/xen/arch/x86/domctl.c b/xen/arch/x86/domctl.c
index fa5e6d4..0aa9f34 100644
--- a/xen/arch/x86/domctl.c
+++ b/xen/arch/x86/domctl.c
@@ -1468,6 +1468,12 @@ long arch_do_domctl(
PSR_VAL_TYPE_L2);
break;
+ case XEN_DOMCTL_PSR_MBA_OP_SET_THRTL:
+ ret = psr_set_val(d, domctl->u.psr_alloc_op.target,
+ domctl->u.psr_alloc_op.data,
+ PSR_VAL_TYPE_MBA);
+ break;
+
case XEN_DOMCTL_PSR_CAT_OP_GET_L3_CBM:
ret = psr_get_val(d, domctl->u.psr_alloc_op.target,
&val32, PSR_VAL_TYPE_L3);
diff --git a/xen/arch/x86/psr.c b/xen/arch/x86/psr.c
index c75755b..dafbbb0 100644
--- a/xen/arch/x86/psr.c
+++ b/xen/arch/x86/psr.c
@@ -136,6 +136,12 @@ static const struct feat_props {
/* write_msr is used to write out feature MSR register. */
void (*write_msr)(unsigned int cos, uint32_t val, enum psr_val_type type);
+
+ /*
+ * check_change_val is used to check if input val fulfills SDM requirement.
+ * Change it to valid value if SDM allows.
+ */
+ bool (*check_change_val)(const struct feat_node *feat, unsigned long *val);
} *feat_props[FEAT_TYPE_NUM];
/*
@@ -273,29 +279,6 @@ static enum psr_feat_type psr_val_type_to_feat_type(enum
psr_val_type type)
return feat_type;
}
-static bool psr_check_cbm(unsigned int cbm_len, unsigned long cbm)
-{
- unsigned int first_bit, zero_bit;
-
- /* Set bits should only in the range of [0, cbm_len]. */
- if ( cbm & (~0ul << cbm_len) )
- return false;
-
- /* At least one bit need to be set. */
- if ( cbm == 0 )
- return false;
-
- first_bit = find_first_bit(&cbm, cbm_len);
- zero_bit = find_next_zero_bit(&cbm, cbm_len, first_bit);
-
- /* Set bits should be contiguous. */
- if ( zero_bit < cbm_len &&
- find_next_bit(&cbm, cbm_len, zero_bit) < cbm_len )
- return false;
-
- return true;
-}
-
/* CAT common functions implementation. */
static int init_alloc_features(const struct cpuid_leaf *regs,
struct feat_node *feat,
@@ -410,6 +393,31 @@ static bool cat_get_feat_info(const struct feat_node *feat,
return true;
}
+static bool cat_check_change_val(const struct feat_node *feat,
+ unsigned long *cbm)
+{
+ unsigned int first_bit, zero_bit;
+ unsigned int cbm_len = feat->cat_info.cbm_len;
+
+ /* Set bits should only in the range of [0, cbm_len]. */
+ if ( *cbm & (~0ul << cbm_len) )
+ return false;
+
+ /* At least one bit need to be set. */
+ if ( *cbm == 0 )
+ return false;
+
+ first_bit = find_first_bit(cbm, cbm_len);
+ zero_bit = find_next_zero_bit(cbm, cbm_len, first_bit);
+
+ /* Set bits should be contiguous. */
+ if ( zero_bit < cbm_len &&
+ find_next_bit(cbm, cbm_len, zero_bit) < cbm_len )
+ return false;
+
+ return true;
+}
+
/* L3 CAT props */
static void l3_cat_write_msr(unsigned int cos, uint32_t val,
enum psr_val_type type)
@@ -423,6 +431,7 @@ static const struct feat_props l3_cat_props = {
.alt_type = PSR_VAL_TYPE_UNKNOWN,
.get_feat_info = cat_get_feat_info,
.write_msr = l3_cat_write_msr,
+ .check_change_val = cat_check_change_val,
};
/* L3 CDP props */
@@ -453,6 +462,7 @@ static const struct feat_props l3_cdp_props = {
.alt_type = PSR_VAL_TYPE_L3,
.get_feat_info = l3_cdp_get_feat_info,
.write_msr = l3_cdp_write_msr,
+ .check_change_val = cat_check_change_val,
};
/* L2 CAT props */
@@ -468,6 +478,7 @@ static const struct feat_props l2_cat_props = {
.alt_type = PSR_VAL_TYPE_UNKNOWN,
.get_feat_info = cat_get_feat_info,
.write_msr = l2_cat_write_msr,
+ .check_change_val = cat_check_change_val,
};
/* MBA props */
@@ -487,6 +498,44 @@ static bool mba_get_feat_info(const struct feat_node *feat,
static void mba_write_msr(unsigned int cos, uint32_t val,
enum psr_val_type type)
{
+ wrmsrl(MSR_IA32_PSR_MBA_MASK(cos), val);
+}
+
+static bool mba_check_change_val(const struct feat_node *feat,
+ unsigned long *thrtl)
+{
+ if ( *thrtl > feat->mba_info.thrtl_max )
+ return false;
+
+ /*
+ * Per SDM (chapter "Memory Bandwidth Allocation Configuration"):
+ * 1. Linear mode: In the linear mode the input precision is defined
+ * as 100-(MBA_MAX). For instance, if the MBA_MAX value is 90, the
+ * input precision is 10%. Values not an even multiple of the
+ * precision (e.g., 12%) will be rounded down (e.g., to 10% delay
+ * applied).
+ * 2. Non-linear mode: Input delay values are powers-of-two from zero
+ * to the MBA_MAX value from CPUID. In this case any values not a
+ * power of two will be rounded down the next nearest power of two.
+ */
+ if ( feat->mba_info.linear )
+ {
+ unsigned int mod;
+
+ if ( feat->mba_info.thrtl_max >= 100 )
+ return false;
+
+ mod = *thrtl % (100 - feat->mba_info.thrtl_max);
+ *thrtl -= mod;
+ }
+ else
+ {
+ /* Not power of 2. */
+ if ( *thrtl & (*thrtl - 1) )
+ *thrtl = *thrtl & (1 << (flsl(*thrtl) - 1));
+ }
+
+ return true;
}
static const struct feat_props mba_props = {
@@ -495,6 +544,7 @@ static const struct feat_props mba_props = {
.alt_type = PSR_VAL_TYPE_UNKNOWN,
.get_feat_info = mba_get_feat_info,
.write_msr = mba_write_msr,
+ .check_change_val = mba_check_change_val,
};
static void __init parse_psr_bool(char *s, char *value, char *feature,
@@ -915,6 +965,7 @@ static int insert_val_into_array(uint32_t val[],
const struct feat_node *feat;
const struct feat_props *props;
unsigned int i;
+ unsigned long check_val = new_val;
int ret;
ASSERT(feat_type < FEAT_TYPE_NUM);
@@ -939,9 +990,11 @@ static int insert_val_into_array(uint32_t val[],
if ( array_len < props->cos_num )
return -ENOSPC;
- if ( !psr_check_cbm(feat->cat_info.cbm_len, new_val) )
+ if ( !props->check_change_val(feat, &check_val) )
return -EINVAL;
+ new_val = check_val;
+
/*
* Value setting position is same as feature array.
* For CDP, user may set both DATA and CODE to same value. For such case,
@@ -1167,28 +1220,74 @@ static unsigned int get_socket_cpu(unsigned int socket)
return nr_cpu_ids;
}
+/*
+ * Because multiple features may co-exist, we need handle all features to write
+ * values of them into a COS register with new COS ID. E.g:
+ * 1. L3 CAT and MBA co-exist.
+ * 2. Dom1 and Dom2 share a same COS ID (2). The L3 CAT CBM of Dom1 is 0x1ff,
+ * the MBA Thrtle of Dom1 is 0xa.
+ * 3. User wants to change MBA Thrtl of Dom1 to be 0x14. Because COS ID 2 is
+ * used by Dom2 too, we have to pick a new COS ID 3. The original values of
+ * Dom1 on COS ID 3 may be below:
+ * ---------
+ * | COS 3 |
+ * ---------
+ * L3 CAT | 0x7ff |
+ * ---------
+ * MBA | 0x0 |
+ * ---------
+ * 4. After setting, the L3 CAT CBM value of Dom1 should be kept and the new
MBA
+ * Thrtl is set. So, the values on COS ID 3 should be below.
+ * ---------
+ * | COS 3 |
+ * ---------
+ * L3 CAT | 0x1ff |
+ * ---------
+ * MBA | 0x14 |
+ * ---------
+ *
+ * So, we should write all features values into their MSRs. That requires the
+ * feature array, feature properties array and value array are input.
+ */
struct cos_write_info
{
unsigned int cos;
- struct feat_node *feature;
+ struct feat_node **features;
const uint32_t *val;
- const struct feat_props *props;
+ unsigned int array_len;
+ const struct feat_props **props;
};
static void do_write_psr_msrs(void *data)
{
const struct cos_write_info *info = data;
- struct feat_node *feat = info->feature;
- const struct feat_props *props = info->props;
- unsigned int i, cos = info->cos, cos_num = props->cos_num;
+ unsigned int i, j, index = 0, array_len = info->array_len, cos = info->cos;
+ const uint32_t *val_array = info->val;
- for ( i = 0; i < cos_num; i++ )
+ for ( i = 0; i < ARRAY_SIZE(feat_props); i++ )
{
- if ( feat->cos_reg_val[cos * cos_num + i] != info->val[i] )
+ struct feat_node *feat = info->features[i];
+ const struct feat_props *props = info->props[i];
+ unsigned int cos_num;
+
+ if ( !feat || !props )
+ continue;
+
+ cos_num = props->cos_num;
+ if ( array_len < cos_num )
+ return;
+
+ for ( j = 0; j < cos_num; j++ )
{
- feat->cos_reg_val[cos * cos_num + i] = info->val[i];
- props->write_msr(cos, info->val[i], props->type[i]);
+ if ( feat->cos_reg_val[cos * cos_num + j] != val_array[index + j] )
+ {
+ feat->cos_reg_val[cos * cos_num + j] = val_array[index + j];
+ props->write_msr(cos, val_array[index + j], props->type[j]);
+ }
}
+
+ array_len -= cos_num;
+ index += cos_num;
}
}
@@ -1196,30 +1295,19 @@ static int write_psr_msrs(unsigned int socket, unsigned
int cos,
const uint32_t val[], unsigned int array_len,
enum psr_feat_type feat_type)
{
- int ret;
struct psr_socket_info *info = get_socket_info(socket);
struct cos_write_info data =
{
.cos = cos,
- .feature = info->features[feat_type],
- .props = feat_props[feat_type],
+ .features = info->features,
+ .val = val,
+ .array_len = array_len,
+ .props = feat_props,
};
if ( cos > info->features[feat_type]->cos_max )
return -EINVAL;
- /* Skip to the feature's value head. */
- ret = skip_prior_features(&array_len, feat_type);
- if ( ret < 0 )
- return ret;
- else
- val += ret;
-
- if ( array_len < feat_props[feat_type]->cos_num )
- return -ENOSPC;
-
- data.val = val;
-
if ( socket == cpu_to_socket(smp_processor_id()) )
do_write_psr_msrs(&data);
else
diff --git a/xen/include/public/domctl.h b/xen/include/public/domctl.h
index 319666e..33dc909 100644
--- a/xen/include/public/domctl.h
+++ b/xen/include/public/domctl.h
@@ -1144,6 +1144,7 @@ struct xen_domctl_psr_alloc_op {
#define XEN_DOMCTL_PSR_CAT_OP_GET_L3_DATA 5
#define XEN_DOMCTL_PSR_CAT_OP_SET_L2_CBM 6
#define XEN_DOMCTL_PSR_CAT_OP_GET_L2_CBM 7
+#define XEN_DOMCTL_PSR_MBA_OP_SET_THRTL 8
#define XEN_DOMCTL_PSR_MBA_OP_GET_THRTL 9
uint32_t cmd; /* IN: XEN_DOMCTL_PSR_CAT_OP_* */
uint32_t target; /* IN */
--
1.9.1
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