Commit 0043b290 authored by Christoffer Dall's avatar Christoffer Dall Committed by Oliver Upton
Browse files

KVM: arm64: nv: Add nested virt VCPU primitives for vEL2 VCPU state 



When running a nested hypervisor we commonly have to figure out if
the VCPU mode is running in the context of a guest hypervisor or guest
guest, or just a normal guest.

Add convenient primitives for this.

Reviewed-by: default avatarRussell King (Oracle) <rmk+kernel@armlinux.org.uk>
Signed-off-by: default avatarChristoffer Dall <christoffer.dall@arm.com>
Signed-off-by: default avatarMarc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20230209175820.1939006-8-maz@kernel.org


Signed-off-by: default avatarOliver Upton <oliver.upton@linux.dev>
parent 5305cc2c

arch/arm64/include/asm/kvm_emulate.h

+56 −0
Original line number Diff line number Diff line
@@ -183,6 +183,62 @@ static __always_inline void vcpu_set_reg(struct kvm_vcpu *vcpu, u8 reg_num, 
		vcpu_gp_regs(vcpu)->regs[reg_num] = val;

}



static inline bool vcpu_is_el2_ctxt(const struct kvm_cpu_context *ctxt)

{

	switch (ctxt->regs.pstate & (PSR_MODE32_BIT | PSR_MODE_MASK)) {

	case PSR_MODE_EL2h:

	case PSR_MODE_EL2t:

		return true;

	default:

		return false;

	}

}



static inline bool vcpu_is_el2(const struct kvm_vcpu *vcpu)

{

	return vcpu_is_el2_ctxt(&vcpu->arch.ctxt);

}



static inline bool __vcpu_el2_e2h_is_set(const struct kvm_cpu_context *ctxt)

{

	return ctxt_sys_reg(ctxt, HCR_EL2) & HCR_E2H;

}



static inline bool vcpu_el2_e2h_is_set(const struct kvm_vcpu *vcpu)

{

	return __vcpu_el2_e2h_is_set(&vcpu->arch.ctxt);

}



static inline bool __vcpu_el2_tge_is_set(const struct kvm_cpu_context *ctxt)

{

	return ctxt_sys_reg(ctxt, HCR_EL2) & HCR_TGE;

}



static inline bool vcpu_el2_tge_is_set(const struct kvm_vcpu *vcpu)

{

	return __vcpu_el2_tge_is_set(&vcpu->arch.ctxt);

}



static inline bool __is_hyp_ctxt(const struct kvm_cpu_context *ctxt)

{

	/*

	 * We are in a hypervisor context if the vcpu mode is EL2 or

	 * E2H and TGE bits are set. The latter means we are in the user space

	 * of the VHE kernel. ARMv8.1 ARM describes this as 'InHost'

	 *

	 * Note that the HCR_EL2.{E2H,TGE}={0,1} isn't really handled in the

	 * rest of the KVM code, and will result in a misbehaving guest.

	 */

	return vcpu_is_el2_ctxt(ctxt) ||

		(__vcpu_el2_e2h_is_set(ctxt) && __vcpu_el2_tge_is_set(ctxt)) ||

		__vcpu_el2_tge_is_set(ctxt);

}



static inline bool is_hyp_ctxt(const struct kvm_vcpu *vcpu)

{

	return __is_hyp_ctxt(&vcpu->arch.ctxt);

}



/*

 * The layout of SPSR for an AArch32 state is different when observed from an

 * AArch64 SPSR_ELx or an AArch32 SPSR_*. This function generates the AArch32