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xen/x86: Remove PVH support
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We are replacing existing PVH guests with new implementation.

We are keeping xen_pvh_domain() macro (for now set to zero) because
when we introduce new PVH implementation later in this series we will
reuse current PVH-specific code (xen_pvh_gnttab_setup()), and that
code is conditioned by 'if (xen_pvh_domain())'. (We will also need
a noop xen_pvh_domain() for !CONFIG_XEN_PVH).

Signed-off-by: Boris Ostrovsky <[email protected]>
Reviewed-by: Juergen Gross <[email protected]>
Reviewed-by: Konrad Rzeszutek Wilk <[email protected]>
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Boris Ostrovsky committed Feb 7, 2017
1 parent 5a7670e commit 063334f
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Showing 9 changed files with 54 additions and 307 deletions.
140 changes: 19 additions & 121 deletions arch/x86/xen/enlighten.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -1138,10 +1138,11 @@ void xen_setup_vcpu_info_placement(void)
xen_vcpu_setup(cpu);
}

/* xen_vcpu_setup managed to place the vcpu_info within the
* percpu area for all cpus, so make use of it. Note that for
* PVH we want to use native IRQ mechanism. */
if (have_vcpu_info_placement && !xen_pvh_domain()) {
/*
* xen_vcpu_setup managed to place the vcpu_info within the
* percpu area for all cpus, so make use of it.
*/
if (have_vcpu_info_placement) {
pv_irq_ops.save_fl = __PV_IS_CALLEE_SAVE(xen_save_fl_direct);
pv_irq_ops.restore_fl = __PV_IS_CALLEE_SAVE(xen_restore_fl_direct);
pv_irq_ops.irq_disable = __PV_IS_CALLEE_SAVE(xen_irq_disable_direct);
Expand Down Expand Up @@ -1413,49 +1414,9 @@ static void __init xen_boot_params_init_edd(void)
* Set up the GDT and segment registers for -fstack-protector. Until
* we do this, we have to be careful not to call any stack-protected
* function, which is most of the kernel.
*
* Note, that it is __ref because the only caller of this after init
* is PVH which is not going to use xen_load_gdt_boot or other
* __init functions.
*/
static void __ref xen_setup_gdt(int cpu)
static void xen_setup_gdt(int cpu)
{
if (xen_feature(XENFEAT_auto_translated_physmap)) {
#ifdef CONFIG_X86_64
unsigned long dummy;

load_percpu_segment(cpu); /* We need to access per-cpu area */
switch_to_new_gdt(cpu); /* GDT and GS set */

/* We are switching of the Xen provided GDT to our HVM mode
* GDT. The new GDT has __KERNEL_CS with CS.L = 1
* and we are jumping to reload it.
*/
asm volatile ("pushq %0\n"
"leaq 1f(%%rip),%0\n"
"pushq %0\n"
"lretq\n"
"1:\n"
: "=&r" (dummy) : "0" (__KERNEL_CS));

/*
* While not needed, we also set the %es, %ds, and %fs
* to zero. We don't care about %ss as it is NULL.
* Strictly speaking this is not needed as Xen zeros those
* out (and also MSR_FS_BASE, MSR_GS_BASE, MSR_KERNEL_GS_BASE)
*
* Linux zeros them in cpu_init() and in secondary_startup_64
* (for BSP).
*/
loadsegment(es, 0);
loadsegment(ds, 0);
loadsegment(fs, 0);
#else
/* PVH: TODO Implement. */
BUG();
#endif
return; /* PVH does not need any PV GDT ops. */
}
pv_cpu_ops.write_gdt_entry = xen_write_gdt_entry_boot;
pv_cpu_ops.load_gdt = xen_load_gdt_boot;

Expand All @@ -1466,59 +1427,6 @@ static void __ref xen_setup_gdt(int cpu)
pv_cpu_ops.load_gdt = xen_load_gdt;
}

#ifdef CONFIG_XEN_PVH
/*
* A PV guest starts with default flags that are not set for PVH, set them
* here asap.
*/
static void xen_pvh_set_cr_flags(int cpu)
{

/* Some of these are setup in 'secondary_startup_64'. The others:
* X86_CR0_TS, X86_CR0_PE, X86_CR0_ET are set by Xen for HVM guests
* (which PVH shared codepaths), while X86_CR0_PG is for PVH. */
write_cr0(read_cr0() | X86_CR0_MP | X86_CR0_NE | X86_CR0_WP | X86_CR0_AM);

if (!cpu)
return;
/*
* For BSP, PSE PGE are set in probe_page_size_mask(), for APs
* set them here. For all, OSFXSR OSXMMEXCPT are set in fpu__init_cpu().
*/
if (boot_cpu_has(X86_FEATURE_PSE))
cr4_set_bits_and_update_boot(X86_CR4_PSE);

if (boot_cpu_has(X86_FEATURE_PGE))
cr4_set_bits_and_update_boot(X86_CR4_PGE);
}

/*
* Note, that it is ref - because the only caller of this after init
* is PVH which is not going to use xen_load_gdt_boot or other
* __init functions.
*/
void __ref xen_pvh_secondary_vcpu_init(int cpu)
{
xen_setup_gdt(cpu);
xen_pvh_set_cr_flags(cpu);
}

static void __init xen_pvh_early_guest_init(void)
{
if (!xen_feature(XENFEAT_auto_translated_physmap))
return;

BUG_ON(!xen_feature(XENFEAT_hvm_callback_vector));

xen_pvh_early_cpu_init(0, false);
xen_pvh_set_cr_flags(0);

#ifdef CONFIG_X86_32
BUG(); /* PVH: Implement proper support. */
#endif
}
#endif /* CONFIG_XEN_PVH */

static void __init xen_dom0_set_legacy_features(void)
{
x86_platform.legacy.rtc = 1;
Expand Down Expand Up @@ -1555,24 +1463,17 @@ asmlinkage __visible void __init xen_start_kernel(void)
xen_domain_type = XEN_PV_DOMAIN;

xen_setup_features();
#ifdef CONFIG_XEN_PVH
xen_pvh_early_guest_init();
#endif

xen_setup_machphys_mapping();

/* Install Xen paravirt ops */
pv_info = xen_info;
pv_init_ops = xen_init_ops;
if (!xen_pvh_domain()) {
pv_cpu_ops = xen_cpu_ops;
pv_cpu_ops = xen_cpu_ops;

x86_platform.get_nmi_reason = xen_get_nmi_reason;
}
x86_platform.get_nmi_reason = xen_get_nmi_reason;

if (xen_feature(XENFEAT_auto_translated_physmap))
x86_init.resources.memory_setup = xen_auto_xlated_memory_setup;
else
x86_init.resources.memory_setup = xen_memory_setup;
x86_init.resources.memory_setup = xen_memory_setup;
x86_init.oem.arch_setup = xen_arch_setup;
x86_init.oem.banner = xen_banner;

Expand Down Expand Up @@ -1665,18 +1566,15 @@ asmlinkage __visible void __init xen_start_kernel(void)
/* set the limit of our address space */
xen_reserve_top();

/* PVH: runs at default kernel iopl of 0 */
if (!xen_pvh_domain()) {
/*
* We used to do this in xen_arch_setup, but that is too late
* on AMD were early_cpu_init (run before ->arch_setup()) calls
* early_amd_init which pokes 0xcf8 port.
*/
set_iopl.iopl = 1;
rc = HYPERVISOR_physdev_op(PHYSDEVOP_set_iopl, &set_iopl);
if (rc != 0)
xen_raw_printk("physdev_op failed %d\n", rc);
}
/*
* We used to do this in xen_arch_setup, but that is too late
* on AMD were early_cpu_init (run before ->arch_setup()) calls
* early_amd_init which pokes 0xcf8 port.
*/
set_iopl.iopl = 1;
rc = HYPERVISOR_physdev_op(PHYSDEVOP_set_iopl, &set_iopl);
if (rc != 0)
xen_raw_printk("physdev_op failed %d\n", rc);

#ifdef CONFIG_X86_32
/* set up basic CPUID stuff */
Expand Down
21 changes: 1 addition & 20 deletions arch/x86/xen/mmu.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -1792,10 +1792,6 @@ static void __init set_page_prot_flags(void *addr, pgprot_t prot,
unsigned long pfn = __pa(addr) >> PAGE_SHIFT;
pte_t pte = pfn_pte(pfn, prot);

/* For PVH no need to set R/O or R/W to pin them or unpin them. */
if (xen_feature(XENFEAT_auto_translated_physmap))
return;

if (HYPERVISOR_update_va_mapping((unsigned long)addr, pte, flags))
BUG();
}
Expand Down Expand Up @@ -1902,8 +1898,7 @@ static void __init check_pt_base(unsigned long *pt_base, unsigned long *pt_end,
* level2_ident_pgt, and level2_kernel_pgt. This means that only the
* kernel has a physical mapping to start with - but that's enough to
* get __va working. We need to fill in the rest of the physical
* mapping once some sort of allocator has been set up. NOTE: for
* PVH, the page tables are native.
* mapping once some sort of allocator has been set up.
*/
void __init xen_setup_kernel_pagetable(pgd_t *pgd, unsigned long max_pfn)
{
Expand Down Expand Up @@ -2812,16 +2807,6 @@ static int do_remap_gfn(struct vm_area_struct *vma,

BUG_ON(!((vma->vm_flags & (VM_PFNMAP | VM_IO)) == (VM_PFNMAP | VM_IO)));

if (xen_feature(XENFEAT_auto_translated_physmap)) {
#ifdef CONFIG_XEN_PVH
/* We need to update the local page tables and the xen HAP */
return xen_xlate_remap_gfn_array(vma, addr, gfn, nr, err_ptr,
prot, domid, pages);
#else
return -EINVAL;
#endif
}

rmd.mfn = gfn;
rmd.prot = prot;
/* We use the err_ptr to indicate if there we are doing a contiguous
Expand Down Expand Up @@ -2915,10 +2900,6 @@ int xen_unmap_domain_gfn_range(struct vm_area_struct *vma,
if (!pages || !xen_feature(XENFEAT_auto_translated_physmap))
return 0;

#ifdef CONFIG_XEN_PVH
return xen_xlate_unmap_gfn_range(vma, numpgs, pages);
#else
return -EINVAL;
#endif
}
EXPORT_SYMBOL_GPL(xen_unmap_domain_gfn_range);
37 changes: 2 additions & 35 deletions arch/x86/xen/setup.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -914,39 +914,6 @@ char * __init xen_memory_setup(void)
return "Xen";
}

/*
* Machine specific memory setup for auto-translated guests.
*/
char * __init xen_auto_xlated_memory_setup(void)
{
struct xen_memory_map memmap;
int i;
int rc;

memmap.nr_entries = ARRAY_SIZE(xen_e820_map);
set_xen_guest_handle(memmap.buffer, xen_e820_map);

rc = HYPERVISOR_memory_op(XENMEM_memory_map, &memmap);
if (rc < 0)
panic("No memory map (%d)\n", rc);

xen_e820_map_entries = memmap.nr_entries;

sanitize_e820_map(xen_e820_map, ARRAY_SIZE(xen_e820_map),
&xen_e820_map_entries);

for (i = 0; i < xen_e820_map_entries; i++)
e820_add_region(xen_e820_map[i].addr, xen_e820_map[i].size,
xen_e820_map[i].type);

/* Remove p2m info, it is not needed. */
xen_start_info->mfn_list = 0;
xen_start_info->first_p2m_pfn = 0;
xen_start_info->nr_p2m_frames = 0;

return "Xen";
}

/*
* Set the bit indicating "nosegneg" library variants should be used.
* We only need to bother in pure 32-bit mode; compat 32-bit processes
Expand Down Expand Up @@ -1032,8 +999,8 @@ void __init xen_pvmmu_arch_setup(void)
void __init xen_arch_setup(void)
{
xen_panic_handler_init();
if (!xen_feature(XENFEAT_auto_translated_physmap))
xen_pvmmu_arch_setup();

xen_pvmmu_arch_setup();

#ifdef CONFIG_ACPI
if (!(xen_start_info->flags & SIF_INITDOMAIN)) {
Expand Down
78 changes: 27 additions & 51 deletions arch/x86/xen/smp.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -99,18 +99,8 @@ static void cpu_bringup(void)
local_irq_enable();
}

/*
* Note: cpu parameter is only relevant for PVH. The reason for passing it
* is we can't do smp_processor_id until the percpu segments are loaded, for
* which we need the cpu number! So we pass it in rdi as first parameter.
*/
asmlinkage __visible void cpu_bringup_and_idle(int cpu)
asmlinkage __visible void cpu_bringup_and_idle(void)
{
#ifdef CONFIG_XEN_PVH
if (xen_feature(XENFEAT_auto_translated_physmap) &&
xen_feature(XENFEAT_supervisor_mode_kernel))
xen_pvh_secondary_vcpu_init(cpu);
#endif
cpu_bringup();
cpu_startup_entry(CPUHP_AP_ONLINE_IDLE);
}
Expand Down Expand Up @@ -404,61 +394,47 @@ cpu_initialize_context(unsigned int cpu, struct task_struct *idle)
gdt = get_cpu_gdt_table(cpu);

#ifdef CONFIG_X86_32
/* Note: PVH is not yet supported on x86_32. */
ctxt->user_regs.fs = __KERNEL_PERCPU;
ctxt->user_regs.gs = __KERNEL_STACK_CANARY;
#endif
memset(&ctxt->fpu_ctxt, 0, sizeof(ctxt->fpu_ctxt));

if (!xen_feature(XENFEAT_auto_translated_physmap)) {
ctxt->user_regs.eip = (unsigned long)cpu_bringup_and_idle;
ctxt->flags = VGCF_IN_KERNEL;
ctxt->user_regs.eflags = 0x1000; /* IOPL_RING1 */
ctxt->user_regs.ds = __USER_DS;
ctxt->user_regs.es = __USER_DS;
ctxt->user_regs.ss = __KERNEL_DS;
ctxt->user_regs.eip = (unsigned long)cpu_bringup_and_idle;
ctxt->flags = VGCF_IN_KERNEL;
ctxt->user_regs.eflags = 0x1000; /* IOPL_RING1 */
ctxt->user_regs.ds = __USER_DS;
ctxt->user_regs.es = __USER_DS;
ctxt->user_regs.ss = __KERNEL_DS;

xen_copy_trap_info(ctxt->trap_ctxt);
xen_copy_trap_info(ctxt->trap_ctxt);

ctxt->ldt_ents = 0;
ctxt->ldt_ents = 0;

BUG_ON((unsigned long)gdt & ~PAGE_MASK);
BUG_ON((unsigned long)gdt & ~PAGE_MASK);

gdt_mfn = arbitrary_virt_to_mfn(gdt);
make_lowmem_page_readonly(gdt);
make_lowmem_page_readonly(mfn_to_virt(gdt_mfn));
gdt_mfn = arbitrary_virt_to_mfn(gdt);
make_lowmem_page_readonly(gdt);
make_lowmem_page_readonly(mfn_to_virt(gdt_mfn));

ctxt->gdt_frames[0] = gdt_mfn;
ctxt->gdt_ents = GDT_ENTRIES;
ctxt->gdt_frames[0] = gdt_mfn;
ctxt->gdt_ents = GDT_ENTRIES;

ctxt->kernel_ss = __KERNEL_DS;
ctxt->kernel_sp = idle->thread.sp0;
ctxt->kernel_ss = __KERNEL_DS;
ctxt->kernel_sp = idle->thread.sp0;

#ifdef CONFIG_X86_32
ctxt->event_callback_cs = __KERNEL_CS;
ctxt->failsafe_callback_cs = __KERNEL_CS;
ctxt->event_callback_cs = __KERNEL_CS;
ctxt->failsafe_callback_cs = __KERNEL_CS;
#else
ctxt->gs_base_kernel = per_cpu_offset(cpu);
#endif
ctxt->event_callback_eip =
(unsigned long)xen_hypervisor_callback;
ctxt->failsafe_callback_eip =
(unsigned long)xen_failsafe_callback;
ctxt->user_regs.cs = __KERNEL_CS;
per_cpu(xen_cr3, cpu) = __pa(swapper_pg_dir);
}
#ifdef CONFIG_XEN_PVH
else {
/*
* The vcpu comes on kernel page tables which have the NX pte
* bit set. This means before DS/SS is touched, NX in
* EFER must be set. Hence the following assembly glue code.
*/
ctxt->user_regs.eip = (unsigned long)xen_pvh_early_cpu_init;
ctxt->user_regs.rdi = cpu;
ctxt->user_regs.rsi = true; /* entry == true */
}
ctxt->gs_base_kernel = per_cpu_offset(cpu);
#endif
ctxt->event_callback_eip =
(unsigned long)xen_hypervisor_callback;
ctxt->failsafe_callback_eip =
(unsigned long)xen_failsafe_callback;
ctxt->user_regs.cs = __KERNEL_CS;
per_cpu(xen_cr3, cpu) = __pa(swapper_pg_dir);

ctxt->user_regs.esp = idle->thread.sp0 - sizeof(struct pt_regs);
ctxt->ctrlreg[3] = xen_pfn_to_cr3(virt_to_gfn(swapper_pg_dir));
if (HYPERVISOR_vcpu_op(VCPUOP_initialise, xen_vcpu_nr(cpu), ctxt))
Expand Down
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