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KVM: SVM: Use unsigned integers when dealing with ASIDs

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[ Upstream commit 466eec4a22a76c462781bf6d45cb02cbedf21a61 ]

Convert all local ASID variables and parameters throughout the SEV code
from signed integers to unsigned integers.  As ASIDs are fundamentally
unsigned values, and the global min/max variables are appropriately
unsigned integers, too.

Functionally, this is a glorified nop as KVM guarantees min_sev_asid is
non-zero, and no CPU supports -1u as the _only_ asid, i.e. the signed vs.
unsigned goof won't cause problems in practice.

Opportunistically use sev_get_asid() in sev_flush_encrypted_page() instead
of open coding an equivalent.

Reviewed-by: Tom Lendacky <thomas.lendacky@amd.com>
Link: https://lore.kernel.org/r/20240131235609.4161407-3-seanjc@google.com
Signed-off-by: Sean Christopherson <seanjc@google.com>
Stable-dep-of: 0aa6b90ef9d7 ("KVM: SVM: Add support for allowing zero SEV ASIDs")
Signed-off-by: Sasha Levin <sashal@kernel.org>
This commit is contained in:
Sean Christopherson 2024-01-31 15:56:07 -08:00 committed by Greg Kroah-Hartman
parent 0a583b7ebb
commit 79b79ea2b3
2 changed files with 15 additions and 13 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

18
arch/x86/kvm/svm/sev.c
View File

@ -84,9 +84,10 @@ struct enc_region {
};
/* Called with the sev_bitmap_lock held, or on shutdown */
static int sev_flush_asids(int min_asid, int max_asid)
static int sev_flush_asids(unsigned int min_asid, unsigned int max_asid)
{
int ret, asid, error = 0;
int ret, error = 0;
unsigned int asid;
/* Check if there are any ASIDs to reclaim before performing a flush */
asid = find_next_bit(sev_reclaim_asid_bitmap, nr_asids, min_asid);
@ -116,7 +117,7 @@ static inline bool is_mirroring_enc_context(struct kvm *kvm)
}
/* Must be called with the sev_bitmap_lock held */
static bool __sev_recycle_asids(int min_asid, int max_asid)
static bool __sev_recycle_asids(unsigned int min_asid, unsigned int max_asid)
{
if (sev_flush_asids(min_asid, max_asid))
return false;
@ -143,8 +144,9 @@ static void sev_misc_cg_uncharge(struct kvm_sev_info *sev)
static int sev_asid_new(struct kvm_sev_info *sev)
{
int asid, min_asid, max_asid, ret;
unsigned int asid, min_asid, max_asid;
bool retry = true;
int ret;
WARN_ON(sev->misc_cg);
sev->misc_cg = get_current_misc_cg();
@ -187,7 +189,7 @@ e_uncharge:
return ret;
}
static int sev_get_asid(struct kvm *kvm)
static unsigned int sev_get_asid(struct kvm *kvm)
{
struct kvm_sev_info *sev = &to_kvm_svm(kvm)->sev_info;
@ -284,8 +286,8 @@ e_no_asid:
static int sev_bind_asid(struct kvm *kvm, unsigned int handle, int *error)
{
unsigned int asid = sev_get_asid(kvm);
struct sev_data_activate activate;
int asid = sev_get_asid(kvm);
int ret;
/* activate ASID on the given handle */
@ -2314,7 +2316,7 @@ int sev_cpu_init(struct svm_cpu_data *sd)
*/
static void sev_flush_encrypted_page(struct kvm_vcpu *vcpu, void *va)
{
int asid = to_kvm_svm(vcpu->kvm)->sev_info.asid;
unsigned int asid = sev_get_asid(vcpu->kvm);
/*
* Note! The address must be a kernel address, as regular page walk
@ -2632,7 +2634,7 @@ void sev_es_unmap_ghcb(struct vcpu_svm *svm)
void pre_sev_run(struct vcpu_svm *svm, int cpu)
{
struct svm_cpu_data *sd = per_cpu_ptr(&svm_data, cpu);
int asid = sev_get_asid(svm->vcpu.kvm);
unsigned int asid = sev_get_asid(svm->vcpu.kvm);
/* Assign the asid allocated with this SEV guest */
svm->asid = asid;

10
arch/x86/kvm/trace.h
View File

@ -732,13 +732,13 @@ TRACE_EVENT(kvm_nested_intr_vmexit,
* Tracepoint for nested #vmexit because of interrupt pending
*/
TRACE_EVENT(kvm_invlpga,
TP_PROTO(__u64 rip, int asid, u64 address),
TP_PROTO(__u64 rip, unsigned int asid, u64 address),
TP_ARGS(rip, asid, address),
TP_STRUCT__entry(
__field( __u64, rip )
__field( int, asid )
__field( __u64, address )
__field( __u64, rip )
__field( unsigned int, asid )
__field( __u64, address )
),
TP_fast_assign(
@ -747,7 +747,7 @@ TRACE_EVENT(kvm_invlpga,
__entry->address = address;
),
TP_printk("rip: 0x%016llx asid: %d address: 0x%016llx",
TP_printk("rip: 0x%016llx asid: %u address: 0x%016llx",
__entry->rip, __entry->asid, __entry->address)
);