Add an explicit exit code 'SPINUP_AP' to tell the controlling process that an

AP needs to be activated by spinning up an execution context for it.

The local apic emulation is now completely done in the hypervisor and it will
detect writes to the ICR_LO register that try to bring up the AP. In response
to such writes it will return to userspace with an exit code of SPINUP_AP.

Reviewed by: grehan

1 files changed, 5 insertions, 218 deletions

diff --git a/usr.sbin/bhyve/xmsr.c b/usr.sbin/bhyve/xmsr.c
index cc148d6..9c05f02 100644
--- a/usr.sbin/bhyve/xmsr.c
+++ b/usr.sbin/bhyve/xmsr.c
@@ -29,233 +29,20 @@
 #include <sys/cdefs.h>
 __FBSDID("$FreeBSD$");
 
-#include <sys/param.h>
-#include <x86/apicreg.h>
+#include <sys/types.h>
 
-#include <assert.h>
-#include <stdio.h>
-#include <stdlib.h>
 #include <machine/vmm.h>
 #include <vmmapi.h>
 
-#include "fbsdrun.h"
-#include "xmsr.h"
-
-/*
- * Trampoline for hypervisor direct 64-bit jump.
- *
- *   0  - signature for guest->host verification
- *   8  - kernel virtual address of trampoline
- *  16  - instruction virtual address
- *  24  - stack pointer virtual address
- *  32  - CR3, physical address of kernel page table
- *  40  - 24-byte area for null/code/data GDT entries
- */
-#define MP_V64T_SIG	0xcafebabecafebabeULL
-struct mp_v64tramp {
-	uint64_t	mt_sig;
-	uint64_t	mt_virt;
-	uint64_t	mt_eip;
-	uint64_t	mt_rsp;
-	uint64_t	mt_cr3;
-	uint64_t	mt_gdtr[3];
-};
-
-/*
- * CPU 0 is considered to be the BSP and is set to the RUNNING state.
- * All other CPUs are set up in the INIT state.
- */
-#define BSP  0
-enum cpu_bstate {
-	CPU_S_INIT,
-	CPU_S_SIPI,
-	CPU_S_RUNNING
-} static cpu_b[VM_MAXCPU] = { [BSP] = CPU_S_RUNNING };
+#include <stdio.h>
+#include <stdlib.h>
 
-static void spinup_ap(struct vmctx *, int, int, uint64_t *);
-static void spinup_ap_direct64(struct vmctx *, int, uintptr_t, uint64_t *);
+#include "xmsr.h"
 
 int
 emulate_wrmsr(struct vmctx *ctx, int vcpu, uint32_t code, uint64_t val)
 {
-	int dest;
-	int mode;
-	int thiscpu;
-	int vec;
-	int error, retval;
-	uint64_t rip;
-
-	retval = vcpu;
-	thiscpu = 1 << vcpu;
-
-	/*
-	 * The only MSR value handled is the x2apic CR register
-	 */
-	if (code != 0x830) {
-		printf("Unknown WRMSR code %x, val %lx, cpu %d\n",
-		       code, val, vcpu);
-		exit(1);
-	}
-
-	/*
-	 * The value written to the MSR will generate an IPI to
-	 * a set of CPUs. If this is a SIPI, create the initial
-	 * state for the CPU and switch to it. Otherwise, inject
-	 * an interrupt for the destination CPU(s), and request
-	 * a switch to the next available one by returning -1
-	 */
-	dest = val >> 32;
-	vec = val & APIC_VECTOR_MASK;
-	mode = val & APIC_DELMODE_MASK;
-
-	switch (mode) {
-	case APIC_DELMODE_INIT:		
-		/*
-		 * Ignore legacy de-assert INITs in x2apic mode
-		 */
-		if ((val & APIC_LEVEL_MASK) == APIC_LEVEL_DEASSERT) {
-			break;
-		}
-
-		assert(dest != 0);
-		assert(dest < guest_ncpus);
-		assert(cpu_b[dest] == CPU_S_INIT);
-
-		/*
-		 * Move CPU to wait-for-SIPI state
-		 */
-		error = vcpu_reset(ctx, dest);
-		assert(error == 0);
-
-		cpu_b[dest] = CPU_S_SIPI;
-		break;
-
-	case APIC_DELMODE_STARTUP:
-		assert(dest != 0);
-		assert(dest < guest_ncpus);
-		/*
-		 * Ignore SIPIs in any state other than wait-for-SIPI
-		 */
-		if (cpu_b[dest] != CPU_S_SIPI) {
-			break;
-		}
-
-		/*
-		 * Bring up the AP and signal the main loop that it is
-		 * available and to switch to it.
-		 */
-		spinup_ap(ctx, dest, vec, &rip);
-		cpu_b[dest] = CPU_S_RUNNING;
-		fbsdrun_addcpu(ctx, dest, rip);
-		retval = dest;
-		break;
-
-	default:
-		printf("APIC delivery mode %lx not supported!\n",
-		       val & APIC_DELMODE_MASK);
-		exit(1);
-	}
-
-	return (retval);
-}
-
-/*
- * There are 2 startup modes possible here:
- *  - if the CPU supports 'unrestricted guest' mode, the spinup can
- *    set up the processor state in power-on 16-bit mode, with the CS:IP
- *    init'd to the specified low-mem 4K page.
- *  - if the guest has requested a 64-bit trampoline in the low-mem 4K
- *    page by placing in the specified signature, set up the register
- *    state using register state in the signature. Note that this
- *    requires accessing guest physical memory to read the signature
- *    while 'unrestricted mode' does not.
- */
-static void
-spinup_ap(struct vmctx *ctx, int newcpu, int vector, uint64_t *rip)
-{
-	int error;
-	uint16_t cs;
-	uint64_t desc_base;
-	uint32_t desc_limit, desc_access;
-
-	if (fbsdrun_vmexit_on_hlt()) {
-		error = vm_set_capability(ctx, newcpu, VM_CAP_HALT_EXIT, 1);
-		assert(error == 0);
-	}
-
-	if (fbsdrun_vmexit_on_pause()) {
-		error = vm_set_capability(ctx, newcpu, VM_CAP_PAUSE_EXIT, 1);
-		assert(error == 0);
-	}
-
-	error = vm_set_capability(ctx, newcpu, VM_CAP_UNRESTRICTED_GUEST, 1);
-	if (error) {
-		/*
-		 * If the guest does not support real-mode execution then
-		 * we will bring up the AP directly in 64-bit mode.
-		 */
-		spinup_ap_direct64(ctx, newcpu, vector << PAGE_SHIFT, rip);
-	} else {
-		/*
-		 * Update the %cs and %rip of the guest so that it starts
-		 * executing real mode code at at 'vector << 12'.
-		 */
-		*rip = 0;
-		error = vm_set_register(ctx, newcpu, VM_REG_GUEST_RIP, *rip);
-		assert(error == 0);
-
-		error = vm_get_desc(ctx, newcpu, VM_REG_GUEST_CS, &desc_base,
-				    &desc_limit, &desc_access);
-		assert(error == 0);
-
-		desc_base = vector << PAGE_SHIFT;
-		error = vm_set_desc(ctx, newcpu, VM_REG_GUEST_CS,
-				    desc_base, desc_limit, desc_access);
-		assert(error == 0);
-
-		cs = (vector << PAGE_SHIFT) >> 4;
-		error = vm_set_register(ctx, newcpu, VM_REG_GUEST_CS, cs);
-		assert(error == 0);
-	}
-}
-
-static void
-spinup_ap_direct64(struct vmctx *ctx, int newcpu, uintptr_t gaddr,
-	uint64_t *rip)
-{
-	struct mp_v64tramp *mvt;
-	char *errstr;
-	int error;
-	uint64_t gdtbase;
-
-	mvt = paddr_guest2host(gaddr);
-
-	assert(mvt->mt_sig == MP_V64T_SIG);
-
-	/*
-	 * Set up the 3-entry GDT using memory supplied in the
-	 * guest's trampoline structure.
-	 */
-	vm_setup_freebsd_gdt(mvt->mt_gdtr);
-
-#define  CHECK_ERROR(msg) \
-	if (error != 0) { \
-		errstr = msg; \
-		goto err_exit; \
-	}
-
-        /* entry point */
-	*rip = mvt->mt_eip;
-
-	/* Get the guest virtual address of the GDT */
-        gdtbase = mvt->mt_virt + __offsetof(struct mp_v64tramp, mt_gdtr);
-
-	error = vm_setup_freebsd_registers(ctx, newcpu, mvt->mt_eip,
-					   mvt->mt_cr3, gdtbase, mvt->mt_rsp);
-	CHECK_ERROR("vm_setup_freebsd_registers");
 
-	return;
-err_exit:
-	printf("spinup_ap_direct64: machine state error: %s", errstr);
+	printf("Unknown WRMSR code %x, val %lx, cpu %d\n", code, val, vcpu);
 	exit(1);
 }