[PATCH v4 3/3] svm/sev: Register SEV and SEV-ES ASIDs to the misc controller
From: Vipin Sharma
Date: Tue Mar 30 2021 - 00:43:50 EST
Secure Encrypted Virtualization (SEV) and Secure Encrypted
Virtualization - Encrypted State (SEV-ES) ASIDs are used to encrypt KVMs
on AMD platform. These ASIDs are available in the limited quantities on
a host.
Register their capacity and usage to the misc controller for tracking
via cgroups.
Signed-off-by: Vipin Sharma <vipinsh@xxxxxxxxxx>
Reviewed-by: David Rientjes <rientjes@xxxxxxxxxx>
---
arch/x86/kvm/svm/sev.c | 70 +++++++++++++++++++++++++++++++------
arch/x86/kvm/svm/svm.h | 1 +
include/linux/misc_cgroup.h | 6 ++++
kernel/cgroup/misc.c | 6 ++++
4 files changed, 73 insertions(+), 10 deletions(-)
diff --git a/arch/x86/kvm/svm/sev.c b/arch/x86/kvm/svm/sev.c
index 874ea309279f..214eefb20414 100644
--- a/arch/x86/kvm/svm/sev.c
+++ b/arch/x86/kvm/svm/sev.c
@@ -14,6 +14,7 @@
#include <linux/psp-sev.h>
#include <linux/pagemap.h>
#include <linux/swap.h>
+#include <linux/misc_cgroup.h>
#include <linux/processor.h>
#include <linux/trace_events.h>
#include <asm/fpu/internal.h>
@@ -28,6 +29,21 @@
#define __ex(x) __kvm_handle_fault_on_reboot(x)
+#ifndef CONFIG_KVM_AMD_SEV
+/*
+ * When this config is not defined, SEV feature is not supported and APIs in
+ * this file are not used but this file still gets compiled into the KVM AMD
+ * module.
+ *
+ * We will not have MISC_CG_RES_SEV and MISC_CG_RES_SEV_ES entries in the enum
+ * misc_res_type {} defined in linux/misc_cgroup.h.
+ *
+ * Below macros allow compilation to succeed.
+ */
+#define MISC_CG_RES_SEV MISC_CG_RES_TYPES
+#define MISC_CG_RES_SEV_ES MISC_CG_RES_TYPES
+#endif
+
static u8 sev_enc_bit;
static int sev_flush_asids(void);
static DECLARE_RWSEM(sev_deactivate_lock);
@@ -89,8 +105,19 @@ static bool __sev_recycle_asids(int min_asid, int max_asid)
static int sev_asid_new(struct kvm_sev_info *sev)
{
- int pos, min_asid, max_asid;
+ int pos, min_asid, max_asid, ret;
bool retry = true;
+ enum misc_res_type type;
+
+ type = sev->es_active ? MISC_CG_RES_SEV_ES : MISC_CG_RES_SEV;
+ WARN_ON(sev->misc_cg);
+ sev->misc_cg = get_current_misc_cg();
+ ret = misc_cg_try_charge(type, sev->misc_cg, 1);
+ if (ret) {
+ put_misc_cg(sev->misc_cg);
+ sev->misc_cg = NULL;
+ return ret;
+ }
mutex_lock(&sev_bitmap_lock);
@@ -108,7 +135,8 @@ static int sev_asid_new(struct kvm_sev_info *sev)
goto again;
}
mutex_unlock(&sev_bitmap_lock);
- return -EBUSY;
+ ret = -EBUSY;
+ goto e_uncharge;
}
__set_bit(pos, sev_asid_bitmap);
@@ -116,6 +144,11 @@ static int sev_asid_new(struct kvm_sev_info *sev)
mutex_unlock(&sev_bitmap_lock);
return pos + 1;
+e_uncharge:
+ misc_cg_uncharge(type, sev->misc_cg, 1);
+ put_misc_cg(sev->misc_cg);
+ sev->misc_cg = NULL;
+ return ret;
}
static int sev_get_asid(struct kvm *kvm)
@@ -125,14 +158,15 @@ static int sev_get_asid(struct kvm *kvm)
return sev->asid;
}
-static void sev_asid_free(int asid)
+static void sev_asid_free(struct kvm_sev_info *sev)
{
struct svm_cpu_data *sd;
int cpu, pos;
+ enum misc_res_type type;
mutex_lock(&sev_bitmap_lock);
- pos = asid - 1;
+ pos = sev->asid - 1;
__set_bit(pos, sev_reclaim_asid_bitmap);
for_each_possible_cpu(cpu) {
@@ -141,6 +175,11 @@ static void sev_asid_free(int asid)
}
mutex_unlock(&sev_bitmap_lock);
+
+ type = sev->es_active ? MISC_CG_RES_SEV_ES : MISC_CG_RES_SEV;
+ misc_cg_uncharge(type, sev->misc_cg, 1);
+ put_misc_cg(sev->misc_cg);
+ sev->misc_cg = NULL;
}
static void sev_unbind_asid(struct kvm *kvm, unsigned int handle)
@@ -188,19 +227,20 @@ static int sev_guest_init(struct kvm *kvm, struct kvm_sev_cmd *argp)
asid = sev_asid_new(sev);
if (asid < 0)
return ret;
+ sev->asid = asid;
ret = sev_platform_init(&argp->error);
if (ret)
goto e_free;
sev->active = true;
- sev->asid = asid;
INIT_LIST_HEAD(&sev->regions_list);
return 0;
e_free:
- sev_asid_free(asid);
+ sev_asid_free(sev);
+ sev->asid = 0;
return ret;
}
@@ -1315,12 +1355,12 @@ void sev_vm_destroy(struct kvm *kvm)
mutex_unlock(&kvm->lock);
sev_unbind_asid(kvm, sev->handle);
- sev_asid_free(sev->asid);
+ sev_asid_free(sev);
}
void __init sev_hardware_setup(void)
{
- unsigned int eax, ebx, ecx, edx;
+ unsigned int eax, ebx, ecx, edx, sev_asid_count, sev_es_asid_count;
bool sev_es_supported = false;
bool sev_supported = false;
@@ -1352,7 +1392,11 @@ void __init sev_hardware_setup(void)
if (!sev_reclaim_asid_bitmap)
goto out;
- pr_info("SEV supported: %u ASIDs\n", max_sev_asid - min_sev_asid + 1);
+ sev_asid_count = max_sev_asid - min_sev_asid + 1;
+ if (misc_cg_set_capacity(MISC_CG_RES_SEV, sev_asid_count))
+ goto out;
+
+ pr_info("SEV supported: %u ASIDs\n", sev_asid_count);
sev_supported = true;
/* SEV-ES support requested? */
@@ -1367,7 +1411,11 @@ void __init sev_hardware_setup(void)
if (min_sev_asid == 1)
goto out;
- pr_info("SEV-ES supported: %u ASIDs\n", min_sev_asid - 1);
+ sev_es_asid_count = min_sev_asid - 1;
+ if (misc_cg_set_capacity(MISC_CG_RES_SEV_ES, sev_es_asid_count))
+ goto out;
+
+ pr_info("SEV-ES supported: %u ASIDs\n", sev_es_asid_count);
sev_es_supported = true;
out:
@@ -1382,6 +1430,8 @@ void sev_hardware_teardown(void)
bitmap_free(sev_asid_bitmap);
bitmap_free(sev_reclaim_asid_bitmap);
+ misc_cg_set_capacity(MISC_CG_RES_SEV, 0);
+ misc_cg_set_capacity(MISC_CG_RES_SEV_ES, 0);
sev_flush_asids();
}
diff --git a/arch/x86/kvm/svm/svm.h b/arch/x86/kvm/svm/svm.h
index 39e071fdab0c..9806aaebc37f 100644
--- a/arch/x86/kvm/svm/svm.h
+++ b/arch/x86/kvm/svm/svm.h
@@ -65,6 +65,7 @@ struct kvm_sev_info {
unsigned long pages_locked; /* Number of pages locked */
struct list_head regions_list; /* List of registered regions */
u64 ap_jump_table; /* SEV-ES AP Jump Table address */
+ struct misc_cg *misc_cg; /* For misc cgroup accounting */
};
struct kvm_svm {
diff --git a/include/linux/misc_cgroup.h b/include/linux/misc_cgroup.h
index 1195d36558b4..c5af592481c0 100644
--- a/include/linux/misc_cgroup.h
+++ b/include/linux/misc_cgroup.h
@@ -12,6 +12,12 @@
* Types of misc cgroup entries supported by the host.
*/
enum misc_res_type {
+#ifdef CONFIG_KVM_AMD_SEV
+ /* AMD SEV ASIDs resource */
+ MISC_CG_RES_SEV,
+ /* AMD SEV-ES ASIDs resource */
+ MISC_CG_RES_SEV_ES,
+#endif
MISC_CG_RES_TYPES
};
diff --git a/kernel/cgroup/misc.c b/kernel/cgroup/misc.c
index 4352bc4a3bd5..ec02d963cad1 100644
--- a/kernel/cgroup/misc.c
+++ b/kernel/cgroup/misc.c
@@ -18,6 +18,12 @@
/* Miscellaneous res name, keep it in sync with enum misc_res_type */
static const char *const misc_res_name[] = {
+#ifdef CONFIG_KVM_AMD_SEV
+ /* AMD SEV ASIDs resource */
+ "sev",
+ /* AMD SEV-ES ASIDs resource */
+ "sev_es",
+#endif
};
/* Root misc cgroup */
--
2.31.0.291.g576ba9dcdaf-goog