diff options
| author | Wei Liu <wei.liu@kernel.org> | 2021-02-03 15:04:26 +0000 |
|---|---|---|
| committer | Wei Liu <wei.liu@kernel.org> | 2021-02-11 08:47:06 +0000 |
| commit | 80f73c9f7468b15484e3ee4a29870fc9fa0419cc (patch) | |
| tree | 35e818f37bde5f9a0b00c2c08493cc5b0e7f2296 /arch/x86/hyperv | |
| parent | 99a0f46af6a7715147e81c558d558021aad4e207 (diff) | |
x86/hyperv: handling hypercall page setup for root
When Linux is running as the root partition, the hypercall page will
have already been setup by Hyper-V. Copy the content over to the
allocated page.
Add checks to hv_suspend & co to bail early because they are not
supported in this setup yet.
Signed-off-by: Lillian Grassin-Drake <ligrassi@microsoft.com>
Signed-off-by: Sunil Muthuswamy <sunilmut@microsoft.com>
Signed-off-by: Nuno Das Neves <nunodasneves@linux.microsoft.com>
Co-Developed-by: Lillian Grassin-Drake <ligrassi@microsoft.com>
Co-Developed-by: Sunil Muthuswamy <sunilmut@microsoft.com>
Co-Developed-by: Nuno Das Neves <nunodasneves@linux.microsoft.com>
Signed-off-by: Wei Liu <wei.liu@kernel.org>
Reviewed-by: Michael Kelley <mikelley@microsoft.com>
Link: https://lore.kernel.org/r/20210203150435.27941-8-wei.liu@kernel.org
Diffstat (limited to 'arch/x86/hyperv')
| -rw-r--r-- | arch/x86/hyperv/hv_init.c | 37 |
1 files changed, 34 insertions, 3 deletions
diff --git a/arch/x86/hyperv/hv_init.c b/arch/x86/hyperv/hv_init.c index 612c555fb9aa..aeea8fbf3c23 100644 --- a/arch/x86/hyperv/hv_init.c +++ b/arch/x86/hyperv/hv_init.c @@ -27,6 +27,7 @@ #include <linux/cpuhotplug.h> #include <linux/syscore_ops.h> #include <clocksource/hyperv_timer.h> +#include <linux/highmem.h> int hyperv_init_cpuhp; u64 hv_current_partition_id = ~0ull; @@ -286,6 +287,9 @@ static int hv_suspend(void) union hv_x64_msr_hypercall_contents hypercall_msr; int ret; + if (hv_root_partition) + return -EPERM; + /* * Reset the hypercall page as it is going to be invalidated * accross hibernation. Setting hv_hypercall_pg to NULL ensures @@ -454,8 +458,35 @@ void __init hyperv_init(void) rdmsrl(HV_X64_MSR_HYPERCALL, hypercall_msr.as_uint64); hypercall_msr.enable = 1; - hypercall_msr.guest_physical_address = vmalloc_to_pfn(hv_hypercall_pg); - wrmsrl(HV_X64_MSR_HYPERCALL, hypercall_msr.as_uint64); + + if (hv_root_partition) { + struct page *pg; + void *src, *dst; + + /* + * For the root partition, the hypervisor will set up its + * hypercall page. The hypervisor guarantees it will not show + * up in the root's address space. The root can't change the + * location of the hypercall page. + * + * Order is important here. We must enable the hypercall page + * so it is populated with code, then copy the code to an + * executable page. + */ + wrmsrl(HV_X64_MSR_HYPERCALL, hypercall_msr.as_uint64); + + pg = vmalloc_to_page(hv_hypercall_pg); + dst = kmap(pg); + src = memremap(hypercall_msr.guest_physical_address << PAGE_SHIFT, PAGE_SIZE, + MEMREMAP_WB); + BUG_ON(!(src && dst)); + memcpy(dst, src, HV_HYP_PAGE_SIZE); + memunmap(src); + kunmap(pg); + } else { + hypercall_msr.guest_physical_address = vmalloc_to_pfn(hv_hypercall_pg); + wrmsrl(HV_X64_MSR_HYPERCALL, hypercall_msr.as_uint64); + } /* * hyperv_init() is called before LAPIC is initialized: see @@ -604,7 +635,7 @@ EXPORT_SYMBOL_GPL(hv_is_hyperv_initialized); bool hv_is_hibernation_supported(void) { - return acpi_sleep_state_supported(ACPI_STATE_S4); + return !hv_root_partition && acpi_sleep_state_supported(ACPI_STATE_S4); } EXPORT_SYMBOL_GPL(hv_is_hibernation_supported); |