diff options
| -rw-r--r-- | src/arch/x86/drivers/hyperv/hyperv.c | 113 | ||||
| -rw-r--r-- | src/arch/x86/drivers/hyperv/hyperv.h | 6 |
2 files changed, 108 insertions, 11 deletions
diff --git a/src/arch/x86/drivers/hyperv/hyperv.c b/src/arch/x86/drivers/hyperv/hyperv.c index f73829bd..cc6e3868 100644 --- a/src/arch/x86/drivers/hyperv/hyperv.c +++ b/src/arch/x86/drivers/hyperv/hyperv.c @@ -39,6 +39,7 @@ FILE_LICENCE ( GPL2_OR_LATER_OR_UBDL ); #include <pic8259.h> #include <ipxe/malloc.h> #include <ipxe/device.h> +#include <ipxe/timer.h> #include <ipxe/cpuid.h> #include <ipxe/msr.h> #include <ipxe/hyperv.h> @@ -51,6 +52,12 @@ FILE_LICENCE ( GPL2_OR_LATER_OR_UBDL ); */ #define HV_MESSAGE_MAX_WAIT_MS 1000 +/** Hyper-V timer frequency (fixed 10Mhz) */ +#define HV_TIMER_HZ 10000000 + +/** Hyper-V timer scale factor (used to avoid 64-bit division) */ +#define HV_TIMER_SHIFT 18 + /** * Convert a Hyper-V status code to an iPXE status code * @@ -145,22 +152,19 @@ static void hv_free_message ( struct hv_hypervisor *hv ) { /** * Check whether or not we are running in Hyper-V * - * @v hv Hyper-V hypervisor * @ret rc Return status code */ -static int hv_check_hv ( struct hv_hypervisor *hv ) { +static int hv_check_hv ( void ) { struct x86_features features; uint32_t interface_id; uint32_t discard_ebx; uint32_t discard_ecx; uint32_t discard_edx; - uint32_t available; - uint32_t permissions; /* Check for presence of a hypervisor (not necessarily Hyper-V) */ x86_features ( &features ); if ( ! ( features.intel.ecx & CPUID_FEATURES_INTEL_ECX_HYPERVISOR ) ) { - DBGC ( hv, "HV %p not running in a hypervisor\n", hv ); + DBGC ( HV_INTERFACE_ID, "HV not running in a hypervisor\n" ); return -ENODEV; } @@ -168,11 +172,26 @@ static int hv_check_hv ( struct hv_hypervisor *hv ) { cpuid ( HV_CPUID_INTERFACE_ID, &interface_id, &discard_ebx, &discard_ecx, &discard_edx ); if ( interface_id != HV_INTERFACE_ID ) { - DBGC ( hv, "HV %p not running in Hyper-V (interface ID " - "%#08x)\n", hv, interface_id ); + DBGC ( HV_INTERFACE_ID, "HV not running in Hyper-V (interface " + "ID %#08x)\n", interface_id ); return -ENODEV; } + return 0; +} + +/** + * Check required features + * + * @v hv Hyper-V hypervisor + * @ret rc Return status code + */ +static int hv_check_features ( struct hv_hypervisor *hv ) { + uint32_t available; + uint32_t permissions; + uint32_t discard_ecx; + uint32_t discard_edx; + /* Check that required features and privileges are available */ cpuid ( HV_CPUID_FEATURES, &available, &permissions, &discard_ecx, &discard_edx ); @@ -509,6 +528,10 @@ static int hv_probe ( struct root_device *rootdev ) { struct hv_hypervisor *hv; int rc; + /* Check we are running in Hyper-V */ + if ( ( rc = hv_check_hv() ) != 0 ) + goto err_check_hv; + /* Allocate and initialise structure */ hv = zalloc ( sizeof ( *hv ) ); if ( ! hv ) { @@ -516,9 +539,9 @@ static int hv_probe ( struct root_device *rootdev ) { goto err_alloc; } - /* Check we are running in Hyper-V */ - if ( ( rc = hv_check_hv ( hv ) ) != 0 ) - goto err_check_hv; + /* Check features */ + if ( ( rc = hv_check_features ( hv ) ) != 0 ) + goto err_check_features; /* Allocate pages */ if ( ( rc = hv_alloc_pages ( hv, &hv->hypercall, &hv->synic.message, @@ -555,9 +578,10 @@ static int hv_probe ( struct root_device *rootdev ) { hv_free_pages ( hv, hv->hypercall, hv->synic.message, hv->synic.event, NULL ); err_alloc_pages: - err_check_hv: + err_check_features: free ( hv ); err_alloc: + err_check_hv: return rc; } @@ -590,6 +614,73 @@ struct root_device hv_root_device __root_device = { .driver = &hv_root_driver, }; +/** + * Probe timer + * + * @ret rc Return status code + */ +static int hv_timer_probe ( void ) { + uint32_t available; + uint32_t discard_ebx; + uint32_t discard_ecx; + uint32_t discard_edx; + int rc; + + /* Check we are running in Hyper-V */ + if ( ( rc = hv_check_hv() ) != 0 ) + return rc; + + /* Check for available reference counter */ + cpuid ( HV_CPUID_FEATURES, &available, &discard_ebx, &discard_ecx, + &discard_edx ); + if ( ! ( available & HV_FEATURES_AVAIL_TIME_REF_COUNT_MSR ) ) { + DBGC ( HV_INTERFACE_ID, "HV has no time reference counter\n" ); + return -ENODEV; + } + + return 0; +} + +/** + * Get current system time in ticks + * + * @ret ticks Current time, in ticks + */ +static unsigned long hv_currticks ( void ) { + + /* Calculate time using a combination of bit shifts and + * multiplication (to avoid a 64-bit division). + */ + return ( ( rdmsr ( HV_X64_MSR_TIME_REF_COUNT ) >> HV_TIMER_SHIFT ) * + ( TICKS_PER_SEC / ( HV_TIMER_HZ >> HV_TIMER_SHIFT ) ) ); +} + +/** + * Delay for a fixed number of microseconds + * + * @v usecs Number of microseconds for which to delay + */ +static void hv_udelay ( unsigned long usecs ) { + uint32_t start; + uint32_t elapsed; + uint32_t threshold; + + /* Spin until specified number of 10MHz ticks have elapsed */ + start = rdmsr ( HV_X64_MSR_TIME_REF_COUNT ); + threshold = ( usecs * ( HV_TIMER_HZ / 1000000 ) ); + do { + elapsed = ( rdmsr ( HV_X64_MSR_TIME_REF_COUNT ) - start ); + } while ( elapsed < threshold ); +} + +/** Hyper-V timer */ +struct timer hv_timer __timer ( TIMER_PREFERRED ) = { + .name = "Hyper-V", + .probe = hv_timer_probe, + .currticks = hv_currticks, + .udelay = hv_udelay, +}; + /* Drag in objects via hv_root_device */ REQUIRING_SYMBOL ( hv_root_device ); diff --git a/src/arch/x86/drivers/hyperv/hyperv.h b/src/arch/x86/drivers/hyperv/hyperv.h index 0d09beb4..08031fc6 100644 --- a/src/arch/x86/drivers/hyperv/hyperv.h +++ b/src/arch/x86/drivers/hyperv/hyperv.h @@ -21,6 +21,9 @@ FILE_LICENCE ( GPL2_OR_LATER_OR_UBDL ); /** Get hypervisor features */ #define HV_CPUID_FEATURES 0x40000003UL +/** Time reference counter MSR is available */ +#define HV_FEATURES_AVAIL_TIME_REF_COUNT_MSR 0x00000002UL + /** SynIC MSRs are available */ #define HV_FEATURES_AVAIL_SYNIC_MSR 0x00000004UL @@ -39,6 +42,9 @@ FILE_LICENCE ( GPL2_OR_LATER_OR_UBDL ); /** Hypercall page MSR */ #define HV_X64_MSR_HYPERCALL 0x40000001UL +/** Time reference MSR */ +#define HV_X64_MSR_TIME_REF_COUNT 0x40000020UL + /** SynIC control MSR */ #define HV_X64_MSR_SCONTROL 0x40000080UL |