Commit d7fc7d98 authored by Ashish Kalra's avatar Ashish Kalra Committed by Sean Christopherson
Browse files

KVM: SEV: Introduce new min,max sev_es and sev_snp asid variables 



Introduce new min, max sev_es_asid and sev_snp_asid variables.

The new {min,max}_{sev_es,snp}_asid variables along with existing
{min,max}_sev_asid variable simplifies partitioning of the
SEV and SEV-ES+ ASID space.

Suggested-by: default avatarSean Christopherson <seanjc@google.com>
Reviewed-by: default avatarTom Lendacky <thomas.lendacky@amd.com>
Signed-off-by: default avatarAshish Kalra <ashish.kalra@amd.com>
Link: https://lore.kernel.org/r/1db48277e8e96a633d734786ea69bf830f014857.1755721927.git.ashish.kalra@amd.com


Signed-off-by: default avatarSean Christopherson <seanjc@google.com>
parent c9760b0f

arch/x86/kvm/svm/sev.c

+27 −9
Original line number Diff line number Diff line
@@ -85,6 +85,10 @@ static DECLARE_RWSEM(sev_deactivate_lock); 
static DEFINE_MUTEX(sev_bitmap_lock);

unsigned int max_sev_asid;

static unsigned int min_sev_asid;

static unsigned int max_sev_es_asid;

static unsigned int min_sev_es_asid;

static unsigned int max_snp_asid;

static unsigned int min_snp_asid;

static unsigned long sev_me_mask;

static unsigned int nr_asids;

static unsigned long *sev_asid_bitmap;
@@ -173,20 +177,31 @@ static void sev_misc_cg_uncharge(struct kvm_sev_info *sev) 
	misc_cg_uncharge(type, sev->misc_cg, 1);

}



static int sev_asid_new(struct kvm_sev_info *sev)

static int sev_asid_new(struct kvm_sev_info *sev, unsigned long vm_type)

{

	/*

	 * SEV-enabled guests must use asid from min_sev_asid to max_sev_asid.

	 * SEV-ES-enabled guest can use from 1 to min_sev_asid - 1.

	 * Note: min ASID can end up larger than the max if basic SEV support is

	 * effectively disabled by disallowing use of ASIDs for SEV guests.

	 */

	unsigned int min_asid = sev->es_active ? 1 : min_sev_asid;

	unsigned int max_asid = sev->es_active ? min_sev_asid - 1 : max_sev_asid;

	unsigned int asid;

	unsigned int min_asid, max_asid, asid;

	bool retry = true;

	int ret;



	if (vm_type == KVM_X86_SNP_VM) {

		min_asid = min_snp_asid;

		max_asid = max_snp_asid;

	} else if (sev->es_active) {

		min_asid = min_sev_es_asid;

		max_asid = max_sev_es_asid;

	} else {

		min_asid = min_sev_asid;

		max_asid = max_sev_asid;

	}



	/*

	 * The min ASID can end up larger than the max if basic SEV support is

	 * effectively disabled by disallowing use of ASIDs for SEV guests.

	 */

	if (min_asid > max_asid)

		return -ENOTTY;
@@ -440,7 +455,7 @@ static int __sev_guest_init(struct kvm *kvm, struct kvm_sev_cmd *argp, 
	if (vm_type == KVM_X86_SNP_VM)

		sev->vmsa_features |= SVM_SEV_FEAT_SNP_ACTIVE;



	ret = sev_asid_new(sev);

	ret = sev_asid_new(sev, vm_type);

	if (ret)

		goto e_no_asid;
@@ -3042,6 +3057,9 @@ void __init sev_hardware_setup(void) 
	if (min_sev_asid == 1)

		goto out;



	min_sev_es_asid = min_snp_asid = 1;

	max_sev_es_asid = max_snp_asid = min_sev_asid - 1;



	sev_es_asid_count = min_sev_asid - 1;

	WARN_ON_ONCE(misc_cg_set_capacity(MISC_CG_RES_SEV_ES, sev_es_asid_count));

	sev_es_supported = true;
@@ -3065,11 +3083,11 @@ void __init sev_hardware_setup(void) 
	if (boot_cpu_has(X86_FEATURE_SEV_ES))

		pr_info("SEV-ES %s (ASIDs %u - %u)\n",

			str_enabled_disabled(sev_es_supported),

			min_sev_asid > 1 ? 1 : 0, min_sev_asid - 1);

			min_sev_es_asid, max_sev_es_asid);

	if (boot_cpu_has(X86_FEATURE_SEV_SNP))

		pr_info("SEV-SNP %s (ASIDs %u - %u)\n",

			str_enabled_disabled(sev_snp_supported),

			min_sev_asid > 1 ? 1 : 0, min_sev_asid - 1);

			min_snp_asid, max_snp_asid);



	sev_enabled = sev_supported;

	sev_es_enabled = sev_es_supported;