Commit c72544d8 authored by Radim Krčmář's avatar Radim Krčmář
Browse files

Merge branch 'kvm-ppc-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/paulus/powerpc 

* fix problems that could cause hangs or crashes in the host on POWER9
* fix problems that could allow guests to potentially affect or disrupt
  the execution of the controlling userspace
parents 41f1830f 3d3efb68

arch/powerpc/kvm/book3s_hv.c

+51 −0
Original line number Diff line number Diff line
@@ -1486,6 +1486,14 @@ static int kvmppc_set_one_reg_hv(struct kvm_vcpu *vcpu, u64 id, 
		r = set_vpa(vcpu, &vcpu->arch.dtl, addr, len);

		break;

	case KVM_REG_PPC_TB_OFFSET:

		/*

		 * POWER9 DD1 has an erratum where writing TBU40 causes

		 * the timebase to lose ticks.  So we don't let the

		 * timebase offset be changed on P9 DD1.  (It is

		 * initialized to zero.)

		 */

		if (cpu_has_feature(CPU_FTR_POWER9_DD1))

			break;

		/* round up to multiple of 2^24 */

		vcpu->arch.vcore->tb_offset =

			ALIGN(set_reg_val(id, *val), 1UL << 24);
@@ -2907,12 +2915,36 @@ static int kvmppc_vcpu_run_hv(struct kvm_run *run, struct kvm_vcpu *vcpu) 
{

	int r;

	int srcu_idx;

	unsigned long ebb_regs[3] = {};	/* shut up GCC */

	unsigned long user_tar = 0;

	unsigned int user_vrsave;



	if (!vcpu->arch.sane) {

		run->exit_reason = KVM_EXIT_INTERNAL_ERROR;

		return -EINVAL;

	}



	/*

	 * Don't allow entry with a suspended transaction, because

	 * the guest entry/exit code will lose it.

	 * If the guest has TM enabled, save away their TM-related SPRs

	 * (they will get restored by the TM unavailable interrupt).

	 */

#ifdef CONFIG_PPC_TRANSACTIONAL_MEM

	if (cpu_has_feature(CPU_FTR_TM) && current->thread.regs &&

	    (current->thread.regs->msr & MSR_TM)) {

		if (MSR_TM_ACTIVE(current->thread.regs->msr)) {

			run->exit_reason = KVM_EXIT_FAIL_ENTRY;

			run->fail_entry.hardware_entry_failure_reason = 0;

			return -EINVAL;

		}

		current->thread.tm_tfhar = mfspr(SPRN_TFHAR);

		current->thread.tm_tfiar = mfspr(SPRN_TFIAR);

		current->thread.tm_texasr = mfspr(SPRN_TEXASR);

		current->thread.regs->msr &= ~MSR_TM;

	}

#endif



	kvmppc_core_prepare_to_enter(vcpu);



	/* No need to go into the guest when all we'll do is come back out */
@@ -2934,6 +2966,15 @@ static int kvmppc_vcpu_run_hv(struct kvm_run *run, struct kvm_vcpu *vcpu) 


	flush_all_to_thread(current);



	/* Save userspace EBB and other register values */

	if (cpu_has_feature(CPU_FTR_ARCH_207S)) {

		ebb_regs[0] = mfspr(SPRN_EBBHR);

		ebb_regs[1] = mfspr(SPRN_EBBRR);

		ebb_regs[2] = mfspr(SPRN_BESCR);

		user_tar = mfspr(SPRN_TAR);

	}

	user_vrsave = mfspr(SPRN_VRSAVE);



	vcpu->arch.wqp = &vcpu->arch.vcore->wq;

	vcpu->arch.pgdir = current->mm->pgd;

	vcpu->arch.state = KVMPPC_VCPU_BUSY_IN_HOST;
@@ -2960,6 +3001,16 @@ static int kvmppc_vcpu_run_hv(struct kvm_run *run, struct kvm_vcpu *vcpu) 
		}

	} while (is_kvmppc_resume_guest(r));



	/* Restore userspace EBB and other register values */

	if (cpu_has_feature(CPU_FTR_ARCH_207S)) {

		mtspr(SPRN_EBBHR, ebb_regs[0]);

		mtspr(SPRN_EBBRR, ebb_regs[1]);

		mtspr(SPRN_BESCR, ebb_regs[2]);

		mtspr(SPRN_TAR, user_tar);

		mtspr(SPRN_FSCR, current->thread.fscr);

	}

	mtspr(SPRN_VRSAVE, user_vrsave);



 out:

	vcpu->arch.state = KVMPPC_VCPU_NOTREADY;

	atomic_dec(&vcpu->kvm->arch.vcpus_running);

arch/powerpc/kvm/book3s_hv_interrupts.S

+11 −1
Original line number Diff line number Diff line
@@ -121,10 +121,20 @@ END_FTR_SECTION_IFSET(CPU_FTR_ARCH_207S) 
	 * Put whatever is in the decrementer into the

	 * hypervisor decrementer.

	 */

BEGIN_FTR_SECTION

	ld	r5, HSTATE_KVM_VCORE(r13)

	ld	r6, VCORE_KVM(r5)

	ld	r9, KVM_HOST_LPCR(r6)

	andis.	r9, r9, LPCR_LD@h

END_FTR_SECTION_IFSET(CPU_FTR_ARCH_300)

	mfspr	r8,SPRN_DEC

	mftb	r7

	mtspr	SPRN_HDEC,r8

BEGIN_FTR_SECTION

	/* On POWER9, don't sign-extend if host LPCR[LD] bit is set */

	bne	32f

END_FTR_SECTION_IFSET(CPU_FTR_ARCH_300)

	extsw	r8,r8

32:	mtspr	SPRN_HDEC,r8

	add	r8,r8,r7

	std	r8,HSTATE_DECEXP(r13)

arch/powerpc/kvm/book3s_hv_rmhandlers.S

+56 −19
Original line number Diff line number Diff line
@@ -32,12 +32,29 @@ 
#include <asm/opal.h>

#include <asm/xive-regs.h>



/* Sign-extend HDEC if not on POWER9 */

#define EXTEND_HDEC(reg)			\

BEGIN_FTR_SECTION;				\

	extsw	reg, reg;			\

END_FTR_SECTION_IFCLR(CPU_FTR_ARCH_300)



#define VCPU_GPRS_TM(reg) (((reg) * ULONG_SIZE) + VCPU_GPR_TM)



/* Values in HSTATE_NAPPING(r13) */

#define NAPPING_CEDE	1

#define NAPPING_NOVCPU	2



/* Stack frame offsets for kvmppc_hv_entry */

#define SFS			144

#define STACK_SLOT_TRAP		(SFS-4)

#define STACK_SLOT_TID		(SFS-16)

#define STACK_SLOT_PSSCR	(SFS-24)

#define STACK_SLOT_PID		(SFS-32)

#define STACK_SLOT_IAMR		(SFS-40)

#define STACK_SLOT_CIABR	(SFS-48)

#define STACK_SLOT_DAWR		(SFS-56)

#define STACK_SLOT_DAWRX	(SFS-64)



/*

 * Call kvmppc_hv_entry in real mode.

 * Must be called with interrupts hard-disabled.
@@ -214,6 +231,8 @@ END_FTR_SECTION_IFSET(CPU_FTR_ARCH_207S) 
kvmppc_primary_no_guest:

	/* We handle this much like a ceded vcpu */

	/* put the HDEC into the DEC, since HDEC interrupts don't wake us */

	/* HDEC may be larger than DEC for arch >= v3.00, but since the */

	/* HDEC value came from DEC in the first place, it will fit */

	mfspr	r3, SPRN_HDEC

	mtspr	SPRN_DEC, r3

	/*
@@ -295,8 +314,9 @@ kvm_novcpu_wakeup: 


	/* See if our timeslice has expired (HDEC is negative) */

	mfspr	r0, SPRN_HDEC

	EXTEND_HDEC(r0)

	li	r12, BOOK3S_INTERRUPT_HV_DECREMENTER

	cmpwi	r0, 0

	cmpdi	r0, 0

	blt	kvm_novcpu_exit



	/* Got an IPI but other vcpus aren't yet exiting, must be a latecomer */
@@ -319,10 +339,10 @@ kvm_novcpu_exit: 
	bl	kvmhv_accumulate_time

#endif

13:	mr	r3, r12

	stw	r12, 112-4(r1)

	stw	r12, STACK_SLOT_TRAP(r1)

	bl	kvmhv_commence_exit

	nop

	lwz	r12, 112-4(r1)

	lwz	r12, STACK_SLOT_TRAP(r1)

	b	kvmhv_switch_to_host



/*
@@ -390,8 +410,8 @@ kvm_secondary_got_guest: 
	lbz	r4, HSTATE_PTID(r13)

	cmpwi	r4, 0

	bne	63f

	lis	r6, 0x7fff

	ori	r6, r6, 0xffff

	LOAD_REG_ADDR(r6, decrementer_max)

	ld	r6, 0(r6)

	mtspr	SPRN_HDEC, r6

	/* and set per-LPAR registers, if doing dynamic micro-threading */

	ld	r6, HSTATE_SPLIT_MODE(r13)
@@ -545,11 +565,6 @@ END_FTR_SECTION_IFSET(CPU_FTR_ARCH_207S) 
 *                                                                            *

 *****************************************************************************/



/* Stack frame offsets */

#define STACK_SLOT_TID		(112-16)

#define STACK_SLOT_PSSCR	(112-24)

#define STACK_SLOT_PID		(112-32)



.global kvmppc_hv_entry

kvmppc_hv_entry:
@@ -565,7 +580,7 @@ kvmppc_hv_entry: 
	 */

	mflr	r0

	std	r0, PPC_LR_STKOFF(r1)

	stdu	r1, -112(r1)

	stdu	r1, -SFS(r1)



	/* Save R1 in the PACA */

	std	r1, HSTATE_HOST_R1(r13)
@@ -749,10 +764,20 @@ BEGIN_FTR_SECTION 
	mfspr	r5, SPRN_TIDR

	mfspr	r6, SPRN_PSSCR

	mfspr	r7, SPRN_PID

	mfspr	r8, SPRN_IAMR

	std	r5, STACK_SLOT_TID(r1)

	std	r6, STACK_SLOT_PSSCR(r1)

	std	r7, STACK_SLOT_PID(r1)

	std	r8, STACK_SLOT_IAMR(r1)

END_FTR_SECTION_IFSET(CPU_FTR_ARCH_300)

BEGIN_FTR_SECTION

	mfspr	r5, SPRN_CIABR

	mfspr	r6, SPRN_DAWR

	mfspr	r7, SPRN_DAWRX

	std	r5, STACK_SLOT_CIABR(r1)

	std	r6, STACK_SLOT_DAWR(r1)

	std	r7, STACK_SLOT_DAWRX(r1)

END_FTR_SECTION_IFSET(CPU_FTR_ARCH_207S)



BEGIN_FTR_SECTION

	/* Set partition DABR */
@@ -968,7 +993,8 @@ ALT_FTR_SECTION_END_IFCLR(CPU_FTR_ARCH_300) 


	/* Check if HDEC expires soon */

	mfspr	r3, SPRN_HDEC

	cmpwi	r3, 512		/* 1 microsecond */

	EXTEND_HDEC(r3)

	cmpdi	r3, 512		/* 1 microsecond */

	blt	hdec_soon



#ifdef CONFIG_KVM_XICS
@@ -1505,11 +1531,10 @@ ALT_FTR_SECTION_END_IFCLR(CPU_FTR_ARCH_300) 
	 * set by the guest could disrupt the host.

	 */

	li	r0, 0

	mtspr	SPRN_IAMR, r0

	mtspr	SPRN_CIABR, r0

	mtspr	SPRN_DAWRX, r0

	mtspr	SPRN_PSPB, r0

	mtspr	SPRN_WORT, r0

BEGIN_FTR_SECTION

	mtspr	SPRN_IAMR, r0

	mtspr	SPRN_TCSCR, r0

	/* Set MMCRS to 1<<31 to freeze and disable the SPMC counters */

	li	r0, 1
@@ -1525,6 +1550,7 @@ END_FTR_SECTION_IFCLR(CPU_FTR_ARCH_300) 
	std	r6,VCPU_UAMOR(r9)

	li	r6,0

	mtspr	SPRN_AMR,r6

	mtspr	SPRN_UAMOR, r6



	/* Switch DSCR back to host value */

	mfspr	r8, SPRN_DSCR
@@ -1669,13 +1695,23 @@ END_FTR_SECTION_IFSET(CPU_FTR_ARCH_207S) 
	ptesync



	/* Restore host values of some registers */

BEGIN_FTR_SECTION

	ld	r5, STACK_SLOT_CIABR(r1)

	ld	r6, STACK_SLOT_DAWR(r1)

	ld	r7, STACK_SLOT_DAWRX(r1)

	mtspr	SPRN_CIABR, r5

	mtspr	SPRN_DAWR, r6

	mtspr	SPRN_DAWRX, r7

END_FTR_SECTION_IFSET(CPU_FTR_ARCH_207S)

BEGIN_FTR_SECTION

	ld	r5, STACK_SLOT_TID(r1)

	ld	r6, STACK_SLOT_PSSCR(r1)

	ld	r7, STACK_SLOT_PID(r1)

	ld	r8, STACK_SLOT_IAMR(r1)

	mtspr	SPRN_TIDR, r5

	mtspr	SPRN_PSSCR, r6

	mtspr	SPRN_PID, r7

	mtspr	SPRN_IAMR, r8

END_FTR_SECTION_IFSET(CPU_FTR_ARCH_300)

BEGIN_FTR_SECTION

	PPC_INVALIDATE_ERAT
@@ -1819,8 +1855,8 @@ END_MMU_FTR_SECTION_IFSET(MMU_FTR_TYPE_RADIX) 
	li	r0, KVM_GUEST_MODE_NONE

	stb	r0, HSTATE_IN_GUEST(r13)



	ld	r0, 112+PPC_LR_STKOFF(r1)

	addi	r1, r1, 112

	ld	r0, SFS+PPC_LR_STKOFF(r1)

	addi	r1, r1, SFS

	mtlr	r0

	blr
@@ -2366,12 +2402,13 @@ END_FTR_SECTION_IFSET(CPU_FTR_TM) 
	mfspr	r3, SPRN_DEC

	mfspr	r4, SPRN_HDEC

	mftb	r5

	cmpw	r3, r4

	extsw	r3, r3

	EXTEND_HDEC(r4)

	cmpd	r3, r4

	ble	67f

	mtspr	SPRN_DEC, r4

67:

	/* save expiry time of guest decrementer */

	extsw	r3, r3

	add	r3, r3, r5

	ld	r4, HSTATE_KVM_VCPU(r13)

	ld	r5, HSTATE_KVM_VCORE(r13)