Commit 2239d137 authored by Sean Christopherson's avatar Sean Christopherson
Browse files

KVM: VMX: Compartmentalize adding MSRs to host vs. guest auto-load list 



Undo the bundling of the "host" and "guest" MSR auto-load list logic so
that the code can be deduplicated by factoring out the logic to a separate
helper.  Now that "list full" situations are treated as fatal to the VM,
there is no need to pre-check both lists.

For all intents and purposes, this reverts the add_atomic_switch_msr()
changes made by commit 31907093 ("x86/KVM/VMX: Separate the VMX
AUTOLOAD guest/host number accounting").

Reviewed-by: default avatarDapeng Mi <dapeng1.mi@linux.intel.com>
Tested-by: default avatarManali Shukla <manali.shukla@amd.com>
Link: https://patch.msgid.link/20251206001720.468579-42-seanjc@google.com


Signed-off-by: default avatarSean Christopherson <seanjc@google.com>
parent 0c4ff086

arch/x86/kvm/vmx/vmx.c

+12 −11
Original line number Diff line number Diff line
@@ -1096,9 +1096,9 @@ static __always_inline void add_atomic_switch_msr_special(struct vcpu_vmx *vmx, 
static void add_atomic_switch_msr(struct vcpu_vmx *vmx, unsigned msr,

				  u64 guest_val, u64 host_val)

{

	int i, j = 0;

	struct msr_autoload *m = &vmx->msr_autoload;

	struct kvm *kvm = vmx->vcpu.kvm;

	int i;



	switch (msr) {

	case MSR_EFER:
@@ -1133,25 +1133,26 @@ static void add_atomic_switch_msr(struct vcpu_vmx *vmx, unsigned msr, 
	}



	i = vmx_find_loadstore_msr_slot(&m->guest, msr);

	j = vmx_find_loadstore_msr_slot(&m->host, msr);



	if (KVM_BUG_ON(i < 0 && m->guest.nr == MAX_NR_LOADSTORE_MSRS, kvm) ||

	    KVM_BUG_ON(j < 0 &&  m->host.nr == MAX_NR_LOADSTORE_MSRS, kvm))

	if (i < 0) {

		if (KVM_BUG_ON(m->guest.nr == MAX_NR_LOADSTORE_MSRS, kvm))

			return;



	if (i < 0) {

		i = m->guest.nr++;

		m->guest.val[i].index = msr;

		vmcs_write32(VM_ENTRY_MSR_LOAD_COUNT, m->guest.nr);

	}

	m->guest.val[i].value = guest_val;



	if (j < 0) {

		j = m->host.nr++;

		m->host.val[j].index = msr;

	i = vmx_find_loadstore_msr_slot(&m->host, msr);

	if (i < 0) {

		if (KVM_BUG_ON(m->host.nr == MAX_NR_LOADSTORE_MSRS, kvm))

			return;



		i = m->host.nr++;

		m->host.val[i].index = msr;

		vmcs_write32(VM_EXIT_MSR_LOAD_COUNT, m->host.nr);

	}

	m->host.val[j].value = host_val;

	m->host.val[i].value = host_val;

}



static bool update_transition_efer(struct vcpu_vmx *vmx)